sing的過去式和過去分式

　　Do sing along if you know the words.

　　要是知道歌詞，你就跟著唱吧。

　　I'll sing if I want to ─ there's no law against it.

　　我想唱就唱——誰也管不著。

　　There is some similarity in the way they sing.

　　他們的演唱風格有點像。

　　I can't sing that high.

　　我唱不了那么高的調(diào)子。

　　He doesn't sing all that well.

　　他唱得并不特別好。