岩石圈是指[ ]
A．整个地壳
B．地壳和软流层
C．地壳和上地幔部分
D．地壳和上地幔顶部
答案：D
－ Did Linda see the traffic accident?
－ No, no sooner _____ impossible now does seem possible.[ ]
A. had she gone
B. she had gone
C. has she gone
D. she has gone
HEPA是指（）。
A.通风控制系统
B.高效空气过滤器
C.建筑物排风系统
D.标准操作规范
