自立式起重机在( )及以上风力时应停止作业，并应将吊笼降到地面。
A．三级B．四级C．五级D．六级
参考答案：C
—Excuse me, could you tell me ?
—It’s just 5 minutes’ walk.
A．how far it is to go to Nanjing Museum on foot
B．how far is it to go to Nanjing Museum on foot
C．how long it takes to walk to Nanjing Museum
D．how long does it take to walk to Nanjing Museum
生产一件产品所需要的时间，等于各（）消耗的时间。
A.机床
B.工步
C.工序
