Select the answer with parallel structure. a. last week mark started coming home late, misses classes, and argues with his parents. b. last week mark started to come home late, to miss classes, and arguing. c. last week mark started coming home late, missing classes, and he is arguing with his parents. d. last week mark started coming home late, missing classes, and arguing with his parents.

D. Last week Mark started coming home late, missing classes, and arguing with his parents.

Explanation:

The answer with parallel structure is Last week Mark started coming home late, missing classes, and arguing with his parents. A parallel construction, or a parallel structure joins words, clauses. or phrases. These words, clauses, or phrases should have a parallel grammatical form. All the things that Mark started doing last week are listed in a parallel structure. They are all in the present continuous tense.

your answer is c) experiments with water vapor showed that elements combine in specific proportions.

this question is grammatically incorrect and is illegible to me so i can not answer.