In that case, the combined wave has a lower amplitude than either of the waves did before.

在这种情况下，组合波的 振幅比之前的任何一种波都低。

He either didn't need or want my help or maybe was too embarrassed to accept it. You can also combine " wave" with " down" .

他要么不需要也不想要我的帮助，要么就是太尴尬而不好意思接受。你也可以把“wave”和“down”结合起来。