一定英语短语：

1、by all means：当然可以;一定，务必

2、be bound to do：一定会；一定要做

3、must be：一定是;必须;准是

相关介绍

例句：

By all means take your son with you.

你一定要把儿子带来。

By all means have experts assess your work – but do the first draft yourself.

一定要请专家帮你，但是要在你自己完成了草稿之后。

If you're hungry, by all means, join us for lunch.

如果你饿了，就一定要留下来吃午餐。