Answer:
C. It uses imperfect coordinating structure
Explanation:
Here is just one way to fix the sentence:
The family wants to vacuum, dust, and straighten up the whole house.
What book are you talking about? :)
If you want to use consistent verb tenses in telling a story, that means you have to use the same tense, or at least they all should be in the past/present/future, depending on the first verb in the sentence. Here, the correct answer is:
B) I met Rob for the first time in the school infirmary, and he smiled at me even though he was clearly in pain.
A comparison between two things , typically for the purpose of explanation or clarification.
It's a relative pronoun which introduces a relative clause.
