What experiment can I perform to show that the higher the dissolved oxygen content of water is the better the performance of fish is?

Well, the most important thing about an experiment is to only change one variable at a time, so the variable you would change is dissolved oxygen content. I would have five tanks, one as a control tank with nothing adding or subtracting oxygen, two with supplemented oxygen, and two with reduced oxygen.

To supplement oxygen, it may be cheapest to introduce plants. Unfortunately, however, this will change a variable in the experiment. I would suggest using aeration inside the tank filter, to prevent aerator noise from disturbing the fish. Using a paddle wheel or bubble aerator in the filter would be efficient and cost effective.

To lower the portion of dissolved oxygen, you can saturate the water of the tank with carbon dioxide instead. To do this, I would run a line to a canister of pressurized carbon dioxide, feeding the gas through a bubble aerator in the filter to carbonate the water, occupying the water in the place of oxygen. Be careful with this, however, as it can be somewhat tricky to get a balance of excess carbon dioxide that fish can survive. In the event fish are unable to survive, use the tanks as control or oxygenated tanks instead.

It would be wise to keep tabs on the oxygen content of the tanks while you experiment. I suggest purchasing an oxygen meter for each tank and collecting data continuously. Fish consume resources differently depending on the time of day, activity levels, and other factors.

To test fish 'performance,' I can suggest a few methods. One is to see how active fish are through observation. Better numbers can be taken if you start keeping track of fish deaths in each tank. You can try measuring how much food the fish consume as well- fish may stop eating as much, so scooping out leftover food and weighing it can be a viable method. Certain fish can give clues about their living conditions based on color, like GloFish. Finally, reproductive activity can give clues about fish performance. Fast breeding fish like minnows would work well in that application.

To conclude, make sure you do not change anything besides oxygen between the tanks. Same feeding, same light, same number of fish. Do that, and you have the setup of a good experiment.

How does rhythm function in poetry?

Poetry is a form of literature that uses literary devices such as rhythm, language, image, and symbolism to convey emotional resonance. Poetry comes in many different forms, such as sestina, sonnet, free verse, ekphrastic, concrete, and prose, among many others. In particular, rhythm in poetry is the use of stressed and unstressed syllables that carry throughout the writing. When a poem with a very particular rhythm is read out loud, the result is a reading that projects a distinct cadence. Spoken word poetry, for example, depends heavily on voice intonation and inflection, and therefore it is necessary for each line to convey a certain rhythm or "punchiness." Without adhering to a specific rhythm, the poem (whether spoken or not) can fall flat and lose its effect. That's why every word in poetry needs to be as precise as possible.

What are the phrasal categories of the bold constituents "my friendly neighbor" and "speedily but smoothly" in the following sentences: My...

Any phrase is a group of words that does not include both a subject (person or thing doing an action) and a verb (an action). Groups of words containing both subjects and verbs are instead called clauses. There are many different types of phrases, and the type is determined by the words contained in the phrase and the phrase's function.

In the first sentence, the phrase "my friendly neighbor" is a noun phrase.

A noun phrase contains a noun and its modifiers, such as adjectives and adverbs. Adjectives are words that give further meaning to or describe nouns; adverbs can be used to give further meaning to either verbs or adjectives. Noun phrases will also function as either a subject (person or thing doing the action) or an object (person or thing receiving the action). Dr. Victoria Mikelonis of the University of Minnesota Twin Cities gives us the following example of a noun phrase acting as a subject and containing an adjective:

• 
  The flight attendant drove to Rome.

Here, the phrase "the flight attendant" contains the noun attendant being described by the adjective flight. In addition, it is the flight attendant doing the action of driving. Therefore, we know the whole phrase is a noun phrase acting as a subject.

In the first sentence, the phrase "my friendly neighbor" contains the noun neighbor being modified by the adjective friendly, and it is the "friendly neighbor" who is doing the action of being away; therefore, we know the phrase is a noun phrase acting as a subject.

In the second sentence, "speedily but smoothly" is an adverbial phrase of manner.

Adverbial phrases contain adverbs and other modifying words such as adjectives. There can be adverbial phrases of time, which answer the question when something happened; adverbial phrases of place, which answer the question of where something happened; and adverbial phrases of manner, which answer the question of how something happened. The Cambridge Dictionary (2016) gives us the following example of a sentence containing an adverbial phrase of manner:

• We walked very carefully across the floor.

In this example, the adverbial phrase contains the adverb carefully, which is being modified by the adjective very. Plus, since the phrase explains in what manner the subject in the sentence walked, we know the phrase is an adverbial phrase of manner.

Likewise, in the second sentence, the phrase contains two adverbs: speedily and smoothly. Since the entire phrase explains in what manner the car was driven, we know the phrase is an adverbial phrase of manner.

What are the people in The Chrysalids sheltering themselves from?

I believe that the "people" that the question references are the members of the Waknuk society.  

The people in the Waknuk society are sheltering themselves from and actively fighting against drastic genetic changes.  

The reader learns this detail about the Waknuk people early in the book.  Readers are introduced to Sophie and David in chapter one.  David accidentally discovers that Sophie has six toes, and her parents plead with David to keep it a secret.  

"It's very, very important," she insisted.  "How can I explain to you?"

But she didn't really need to explain. Her urgent, tight-strung feeling of the importance was very plain. Her words were far less potent.

She said: "If anyone were to find out, they'd — they'd be terribly un-kind to her. We've got to see that that never happens."

It was as if the anxious feeling had turned into something hard, like an iron rod.

"Because she has six toes?" I asked.

"Yes. That's what nobody but us must ever know. It must be a secret between us," she repeated, driving it home. "You'll promise, David?"

Their pleading is not so Sophie avoids playground teasing.  They want to keep Sophie alive.  If her genetic mutation becomes known to the Waknuk people, Sophie will either be killed or banished.  

The reader further learns about the Waknuk's deeply ingrained fear of genetic changes when David's house is described.  Hanging up on the walls are "motivational" sayings.  It's akin to people hanging up framed Bible verses in their house.  But the sayings in David's house are hardly positive and uplifting.  They say things like the following:

BLESSED IS THE NORM . . . WATCH THOU FOR THE MUTANT! . . . THE NORM IS THE WILL OF GOD . . . THE DEVIL IS THE FATHER OF DEVIATION.

The Waknuk people are actively seeking shelter from genetic changes.  They actively remove unwanted genetic changes from their population.  Essentially, they are practicing selective breeding, but they are not attempting to breed in new positive traits.  They only want the current, existing traits.   

What happens to the speed of light when it enters glass from water?

When light rays enter one medium from another, refraction takes place. Refraction refers to bending of light rays due to change in the speed of light rays as they move from one medium to another. 

The refractive index of a medium is defined as:

n = c/v

where, n is the refractive index of a medium, c is the speed of light in vacuum and v is the velocity of light in that medium. 

The refractive index of water is about 1.33, while that of glass is around 1.5 - 1.6 (depending on the type of glass). To have a higher refractive index, there are two possibilities:

a) higher value of c, which is not possible, as the speed of light in vacuum is a constant.

b) lower value of v, which is possible.

Thus, the speed of light rays decreases as they enter glass from water. 

In general, when light enters a denser medium from a rarer medium, its speed decreases.

Hope this helps. 

How does Winston's physical appearance differ from O'Brien's in 1984 by George Orwell?

In 1984, there is a strong contrast between the physical appearances of Winston and O'Brien. Winston has a small frame and weathered features, much like a typical worker:

He moved over to the window: a smallish, frail figure, the meagreness of his body merely emphasised by his blue overalls... His hair was very fair, his face naturally sanguine, his skin roughened by coarse soap and blunt razors. 

In contrast, O'Brien is a much larger and stronger-looking man, perhaps representative of his role in the Inner Party:

O’Brien was a large, burly man with a thick neck and a coarse, humorous, brutal face.

In Part Three of the novel, these physical appearances change significantly when Winston is being tortured by O'Brien in the Ministry of Love. Winston is described as a "bowed, grey-coloured skeleton" with "battered-looking cheekbones." O'Brien looks very different, too:

His face… looked coarse and worn, with pouches under the eyes and tired lines from nose to chin.

In Part One of the novel, then, Winston and O'Brien look very different, but by Part Three, their similarities become apparent. Both men are battling rebellion, albeit from different perspectives (Winston is the rebel while O'Brien is the punisher). The emotional impact of this time is evident in their changing physical appearances. This is, perhaps, Orwell's way of stating both men are not so different after all because both, by the end, will love Big Brother. 

How does Vera use the information she learns about Mr. Nuttel to her advantage?

Vera very cautiously and cunningly makes sure that Framton Nuttel is a stranger in this part of the English countryside and would not know anything that would contradict the totally fictitious story she plans to tell him. First she asks, "Do you know many of the people around here?" This is just the sort of question a hostess might ask a visitor like Framton, who is presenting a letter of introduction. 

"Hardly a soul," said Framton. "My sister was staying here, at the rectory, you know, some four years ago, and she gave me letters of introduction to some of the people here."

It should be noted that the author Saki has invented exactly the kind of character who will be a perfect victim for Vera's practical joke. Framton Nuttel is a stranger to the area, he is suffering from a nervous disorder, and his doctors have advised him to rest in the country. As he will tell Mrs. Sappleton shortly later:

"The doctors agree in ordering me complete rest, an absence of mental excitement, and avoidance of anything in the nature of violent physical exercise." 

Ironically, Vera joke will produce just the opposite results, including violent physical exercise when he flees the house and is last seen running for his life down a country road.

Vera continues fishing for information. 

"Then you know practically nothing about my aunt?" pursued the self-possessed young lady.

"Only her name and address," admitted the caller. 

This is enough to satisfy Vera. She doesn't have much time before her aunt will appear and take over as hostess. The girl quickly launches into her story about the three men who went bird-hunting three years ago and were sucked into a bog. If such a tragedy had really happened it would be known all over the region and Framton would have heard about it. Vera has to establish that he is clueless--and Saki has to establish the same thing for the benefit of his readers. Only a complete stranger would do for the role that Framton will play, and only a man who is suffering from what we nowadays would call a severe neurosis would react as spectacularly as Framton does when he sees three armed men approaching the open window in the deepening twilight.

One of the approaching men establishes that they are indeed the three hunters who were supposed to have died when they were sucked into the bog. He breaks into the song which Vera had told Framton he always sang when he returned home at teatime.

Noiselessly they neared the house, and then a hoarse young voice chanted out of the dusk: "I said, Bertie, why do you bound?"

And when Framton turns to look at Vera, he sees that: 

The child was staring out through the open window with a dazed horror in her eyes. 

That does it!

Framton grabbed wildly at his stick and hat; the hall door, the gravel drive, and the front gate were dimly noted stages in his headlong retreat. A cyclist coming along the road had to run into the hedge to avoid imminent collision.