他都没有费心回复我的邮件。

He didn't ___bother to reply to my email.

今晚别费心做饭了；我们点外卖吧。

Don't ___bother cooking tonight; let's order takeout.

说明很清楚，所以何必费心求助呢？

The instructions are clear, so why ___bother asking for help?