______ students in the classroom twenty. The others_____in the library.
A. The number of; is
B. A number of; are
C. The number of; are
The earth is our home . It ______________ well.
| A．must be protected | B．should protect | C．need protect | D．need protecting |
They can’t go out to workthe heavy rain.
| A．because | B．since | C．because of | D．as a result |
－Where _______ the 2008 Olympic Games _______?.
－You don’t know? Beijing!
| A．will; hold | B．has; been held | C．was; held | D．will; held |
______ he is very busy, Li Ming always helps others.
| A．Although | B．If | C．Unless | D．Since |
The visitors our factory two days ago.
| A．got | B．reached in | C．arrived | D．reached |