1.look out 朝外；当心

Do look out for spelling mistakes in your work.
一定要当心你作业中的拼写错误。

He then kept a look out for the restaurants we could dine in for that night.
然后他恋恋不舍的看了看本来那晚我们要去吃饭的餐厅。
2.now and then 有时，时而

Every now and then, however, the intellectuals get itchy feet.
然而，聪明人却不时在蠢蠢欲动。

Now and then I think of when we were together like when you said you felt so happy you could die.
偶尔会想起我们还在一起的时候像当你说你高兴的几乎要死了。

3.at risk 危险

How much are the big u.s. banks at risk in europe?
这些美国大银行的欧洲风险有多高？

The escalating legal battle, however, seems to have put that relationship at risk.
不过不断升级的法律大战可能会危及两者的关系。