The implication of the sentence is just that Milton began to understand the plight of the ducks in his town. When we perceive something, we come to understand it or to "see" it. So, you could say, "I could perceive that Georgette was angry." This means that you could "sense" or "see" that she was angry.

This sentence implies that Reginald couldn't completely disprove the arguments. He was only able to show reasons that they were crazy. When we "refute" something, we show why it is totally wrong or incorrect. Generally, we talk about refuting an argument or a viewpoint. 

All that we know in this sentence is that the king wants the knight to leave the hall and go back to his other duties. We do not know how this happened or even if it was a punishment. Therefore, the best option is the simple word "dismissed," which means to send away. The "dismissal" at the end of the school day is the time when the students are "sent away home." Clearly, these words are related.

The whole point of the sentence is that the man's very long name was written in a shorter form. When we write something in a shorter form like this, we "abbreviate" it. The word "abbreviate" is related to "brief," meaning short. An abbreviation is a shortened form.

Really, all this sentence is stating is that it was necessary to keep extra food in the house. It is not talking about the actual buying of the food—that will be done elsewhere. Therefore, the simple verb "store" is the best option  It means "to keep a supply of something." Actually, we call the places we go shopping "stores" because they are places that keep large supplies of items.

The key clue for this question is the fact that the scientist is working to remove all of the harmful substances in the fluid. This does not mean that he wants to "liquefy" it—it is already a liquid! Also, while he is minimizing the additives, this is not quite the same as saying that he is removing them. When we remove additives or other "extra" material from a substance, we purify that substance. That is what he is doing. Do not be tricked by "scrub." Scrubbing is a physical kind of cleaning that is very particular. It is not a synonym for the general act of purifying.

This sentence seems to indicate that the young man is putting the flower under his jacket. He wants to hide it here so that he does not get caught. When we "conceal" something, we hide it from others' vision. The options "put" and "placed" are broadly "correct." They are not the best options. The best option is the word "concealed" because it expresses the idea of trying to hide the object.

While every answer could be gramatically correct, the term "although" suggests a word that is the opposite of, or different from, what is described in the sentence. "Expensive" and "lengthy" are opposites of a trip to England, as a trip to England is likely to be both expensive and lengthy. There is nothing in the sentence to suggest that Bruce's usual trips are or are not necessary or monotonous. "Domestic" is the best choice because traveling to England is an international trip and domestic in this context means "within one's own country."

Photosynthesis is needed as a food source for plants and thus, it is a vital or important process.

The unique property of water is that its solid form is less dense than its liquid form (water).  This is why ice floats whether in the form of ice cubes in water or an ice layer that covers a pond in the winter.