[usu. in imperative]do not fail (used to emphasize an invitation or instruction)
一定要；务必（用于强调邀请或指示）
[with infinitive]be sure to pop in.
一定要来。
[with clause]be sure that you know what is required.
务必弄清楚要求是什么。
(informal)without doubt
(非正式)毫无疑问
I can't say for sure what Giles really wanted.
我说不准贾尔斯真正想要的是什么。
(亦作 as sure as fate)without any doubt
千真万确，无可置疑
(informal)used to introduce a statement that confirms something previously predicted
(非正式)果真
when X-rays were taken, sure enough, there was the needle.
拍完X光片后，果真有一根针。
very confident of one's own abilities or views
非常自信
he's very sure of himself.
他非常自信。
(informal)a certainty
(非正式)确定无疑的事情
Certainly; unquestionably
确切地；毫无疑问地
We'll win for sure.
我们肯定会获胜
To establish something without doubt; make certain
弄清楚；确保
Make sure he writes it down.
让他一定记下来
Indeed; certainly.
确实；当然