天然气净化厂在净化原料气的同时，能从天然气中回收（），供工农业等使用。
A.甲烷
B.液氨
C.氦
D.硫磺
参考答案：D
As a matter of fact, nearly everybody in the world would like to be ____ Bill Gates is, doing ____ he is doing.
A．where; what
B．what; that
C．that; what
D．who; that
考试的中心环节是()。
A．阅卷
B．监考
C．测验
D．命题
