To understand written material, one must understand the vocabulary.
a. true
b. false

True.

Explanation:

In order to understand the written text or material, it is crucial to understand the vocabulary, as it is difficult or perhaps, impossible to understand the true meaning or essence of the work without knowing the meanings of the vocabulary employed by the author. As we often witness while reading the texts, the author mentions the meaning or context of the particular word(if it's unique or new to the reader) concerning the story, text or poem. This helps the readers and the author both to relate and infer the meaning accordingly. Thus, knowing vocabulary is a must to understand a written piece or text.

because their parents want them to be in the top and get a nice job

explanation:

active voice: my father cut the tree.

passive voice: the tree was cut by my father.

active voice: people buy newspapers every day.

passive voice: newspapers are bought (by people) every day.

active voice: people have been using movies as political propaganda since world war ii.

passive voice: movies have been used as political propaganda since world war ii.

active voice: donna gave me my birthday present.

passive voice: i was given my birthday present (by donna). / my birthday present was given to me (by donna).

active voice: mom will leave the keys on the counter.

passive voice: the keys will be left (by mom) on the counter.

the words in parentheses are the agent of the passive voice and can be omitted when obvious, generic, or simply unnecessary.