《毛 * * 选集》哪一卷被禁止发行()
A.第一卷
B.第二卷
C.第三卷
D.第五卷
参考答案:D
The wider China opens its door to the outside world, the more people find _____important and necessary to study foreign languages.
A.is
B.them
C.it
D.more
小明用40N的水平拉力拉着重200N的物体在水平地面上匀速直线前进了5m,则拉力做的功为( )
A.1000J
B.0J
C.800J
D.200J