阴霾yīn mái
参考答案：
空气中因悬浮着大量的烟、尘等微粒而形成的混沌现象。
单向阀安装时，无方向要求。
--- Mary had a traffic accident and has been sent to the hospital. Did you tell her boss about it?
--- Yes, but I _____ her husband first.
A．should have told
B．shouldn’t have told
C．must have told
D．needn’t have told
