开挖深基坑时，如果分层设置多级平台，每层平台宽度不宜小于（）米。
A.3
B.10
C.1.5
D.5
参考答案：C
云南的道地药材是( )
A．砂仁 B．金银花 C．地黄 D．延胡索 E．三七
--- Could you tell us ______ ?
--- About two weeks.
A．how often are you going to be away
B．how often we are going to be away
C．how long are we going to be away
D．how long we are going to be away
