1. Put on a brave face 假装勇敢，心虚
I was quite scared of snakes, but since my girlfriend was around I had to put on a brave face when I met one.
我很怕蛇，但在女朋友面前我只好假装勇敢，一点都不怕。
释义：put on 除了有穿上衣服之类的意思外，还有“装出，假装”之意。所以习语 put on a brave face，从字面上看就是装出一副勇敢的面孔，假装很勇敢。
2. Put on the back burner 搁置，拖延
As we didn't have the money for that project, we had to put it on the back burner.
我们没有钱实施那个计划，只得暂时搁置一下了。
释义：煤气炉一般有几个火口，前面的火力强，后面的火力弱。
put on the back burner：就在后面的火口上，引申为拖延、搁置。
链接：
put on the front burner 提上日程，优先考虑
