管路系统的特性曲线是随着()的增加而上升。
A、流量
B、扬程
C、轴功率
D、效率
参考答案:A
China’s goal of 7.5 percent GDP growth this year, though moderate in comparison with previous rates, is not cause for concern since it could still generate ________ volume wealth.
A.relative
B.punctual
C.considerable
D.tentative
一个已知力F="10" N,把F分解为F1和F2两个分力,已知分力F1与F的夹角为30°,则F2的大小( )
A.一定小于10 N
B.可能等于10 N
C.可能等于0 N
D.最小等于5 N