【单选题】When we are born, we have 300 bones, but by _______________, we have only 206.
【简答题】A.cut off B.cut across C.cut down D.cut in
【单选题】It's bad to ___________the trees. [ ]
【单选题】They’ve () several scenes in which I appeared.
【单选题】移动式插座的电源连接线应符合( )要求。