—Where ______ they from?
—They're from China.[ ]
A. is
B. am
C. are
C
贵重中药临床用量一般是()
A.0.03~0.6g
B.0.3~1g
C.1~3g
D.3~6g
E.6~9g
电梯处于什么状态时,最远反方向载车信号无效?