软玉是一由透闪石、阳起石为主组成的多矿物集合体，故在正交偏光下呈（）现象。
A.全暗
B.全亮
C.四明四暗
D.异常消光
参考答案：B
-I wonder if I could possibly use your car for tonight?
-________.I'm not using it anyhow.[ ]
A．Sure,go ahead
B．I don't know
C．Yes,indeed
D．I don't care
汽车制动系一般由（）和（）两部分组成。
