01
full of hot air
“full of hot air”直译为“充满热空气”，它还可以表达“吹牛、满口空话”的意思。英文释义为“things that someone says that are intended to sound impressive but do not really mean anything or are not true”。
[例句]
1.David is so full of hot air; all he does is brag about himself.
大卫真是满口空话；他所做的尽是自吹自擂
2.No one believes a word that Tom says because he is full of hot air.
没人相信汤姆说的话，因为他满口火车，整天吹牛。
3.Mary says her boyfriend is the best in the world, but I think she's full of hot air.
玛丽说她的男朋友是世界上最好的男人，我觉得她在吹牛。
02
up in the air
“up in the air”所表达的意思是“尚未定论”，英文释义为“not decided or completely developed， undecided”。
[例句]
1.We have no idea which school she'll be attending in September - everything is still up in the air.
我们不知道她在9月会去哪所学校，还没定下来呢。
2.Because the whole town protested plans to build a new shopping center, that proposal is now up in the air.
由于整个城镇都反对建设新购物中心的计划，因此这提案还没有决定下来。
3.Let's leave this question up in the air until next week.
我们下周再解决这个问题吧。
4.The date of the wedding is still up in the air.
吉期尚未确定。
5.I'm not even sure if my girlfriend will be able to stay in this country. Everything is so up in the air.
我甚至都不知道我女朋友是否能留在这个国家。一切都无法确定。
03
come up for air
短语“come up for air”所表达的意思是“喘口气，调节一下精神”。
[例句]
1.I still have more to do, but I simply have to come up for air. Let’s go out for dinner so I can forget about taxes for a little while.
我还有不少没完成，但是我可真得喘口气歇一下了。我们出去吃顿饭吧，这样我至少可以暂时把报税的事儿丢在脑后。
2.My classmate can sit and study for three or four hours without coming up for air.
我的同学能马不停蹄地一口气学习三四个小时。
3.Thanks for getting me out of the office, Li Hua. I just had to come up for air.
谢谢你把我带出办公室，李华。我不得不出来透透气。
04
put on airs
短语“put on airs”的意思是“摆架子、装腔作势”，一起来看几个例句吧！
[例句]
1.Stop putting on airs, Mary, you're not some world-class actor.
Mary，别摆架子了，你并不是世界级的演员。
2.Although she is a superstar,she never puts on airs.
尽管她是一位超级巨星，但她从不摆架子。
3.He put on airs at the meeting yesterday morning.
他昨天上午在会上装腔作势。
4.My neighbour is always putting on airs.
我的邻居总是装腔作势。