Here, you would need to add the preposition "in."
The sentence should read: My elder sister is really interested in the problems of the environment.
Other prepositions would not make sense and could confuse the reader as to the intended meaning.
Answer:
I think B is the best description of chromosomes because it describes them and gives relevent information about what they do.
Not knowing the story or excerpt you are referring to, I can only help you by asking some questions to get you thinking about the correct answer. Is the village far away from other villages or towns? Are there many sick people in the village making the doctor want to stay away? Is there a lot of violence that the doctor is trying to avoid? What is it about the village or the people in it that the doctor would be trying to avoid? The answer to that questions is the answer to your question.
From the question I don't know if this is right but I would say, something like. It might rain today because you can look up and see if it's going to you don't really need to argue it unless it's bright and sunny with absolutely no clouds, but under normal circumstances others won't test it.
An allusion is a reference to a literary character from a well-known work (for example, Frankenstein, Sherlock Holmes, Biblical characters, etc.). This allows a writer to avoid having to explain all the finer points of his character, by simply pointing the reader to another well-known character. The answer is D.
