Jawaban:

1. a. The wall was being painted by Tina.

b. Their bikes were being repaired by me.

c. This letter had been rewritten by me.

2. a. The passive voice is used to show interest in the person or object that experiences an action rather than the person or object that performs the action. 

b. Conditional sentences are sentences that express one thing contingent on something else, e.g. "If it rains, the picnic will be cancelled". They are so called because the impact of the main clause of the sentence is conditional on the dependent clause.

c. Factual Report is a text that explains and elaborate some factual information relate to particular objects, matter, or things which are based on empirical, real, and/or scientific facts or information.

d. Analytical exposition text is a text that elaborates the writer's idea about the phenomenon. surrounding. Purpose: To persuade the reader or listener that there is something that, certainly, needs to get attention. To analyze a topic and to persuade the reader that this opinion is correct and supported by arguments.