声势的英文：
momentum

The anti-nuclear lobby is becoming stronger.
向议员游说的反核群众声势渐强。

The anti-nuclear lobby is / are becoming stronger
向议员游说的反核群众声势渐强

This- though doubtless it might acquire additional force and volume from the child-
这种欢呼无疑额外增加了声势,表明了当年人们对其统治者孩提式的忠诚

conserve momentum
使动量守恒

This was a campaign that gained momentum.
这是一场势头一直增强的运动。

The tremendous momentum of the Yellow River is inspiring.
黄河的磅礴气势使人振奋。

The gage deflection is due to the momentum transfer.
压力计的偏转是由于动量交换的原因。

This is the well-known principle of conservation of momentum.
这就是众所周知的动量守恒定律。