环境净化与污染控制技术的原理主要包括()、()、()和()。

A)Book a ticket.
B)Leave Beijing.
C)Go to America.
D)Buy some gifts.

A)An engineer
B)A professor.
C)A secretary.
D)A manager.

A)At a book store
B)At a bank.
C)In an office
D)In a restaurant.

A)She can't see the movie today.
B)She doesn't like the movie.
C)She has already seen the movie.
D)She prefers to watch movies alone.