help的形容詞的最高級是？

例句：

The booklet should be very helpful to parents of disabled children.

這本小冊子對於殘疾兒童的.父母會很有用。

Role-play is helpful in developing communication skills.

角色扮演有助於提高溝通技巧。

Sorry I can't be more helpful.

對不起，我幫不上更多的'忙。

You'll find her very helpful ─ if she's not too busy, that is.

你會覺得她很肯幫忙，那是説如果她不太忙的話。

She was very helpful when my mother was ill ─ I'll allow you that.

我母親生病時她幫了很大的忙——我同意你説的這一點。