本文选自《英国大使馆文化教育处》的博客，点击查看博客原文

　　An airhead is someone whose head is full of air. He or she hasn’t got any sensible or realistic ideas and is rather a silly and unintelligent person:

　　例句：Michael forgot to bring his passport for his flight to Sydney. What an airhead!

　　The opposite of an airhead is an egghead. An egghead is a very studious and intellectual person. However it isn’t always used in a complementary manner:

　　John is such an egghead, he should get out more and enjoy himself。

　　Another word for a silly or stupid person is bird brain, whilst an absent-minded person could be called a scatterbrain:

　　例句：Don’t ask Philip to write the proposal. He’s a birdbrain and nobody will accept it。

　　I can’t believe you’ve lost your glasses again Lucy, you are such a scatterbrain。

　　Some people have a brain like a sieve and they can’t remember anything however hard they rack their brains:

　　例句：I have racked my brains but I still can’t remember where I left my glasses. I must have a brain like a sieve!

　　If your head is in the clouds, you are so absorbed in your own thoughts that you pay no attention to what is going on around you:

　　例句：I wish Julia would pay more attention to her teacher; her head is always in the clouds. Why can’t she be more like her brother Ben? His head is screwed on right。

　　On the other hand, if you haven’t got your head screwed on right, you could well have a screw loose which means you are eccentric or even mentally unstable。

　　Finally, sometimes we can’t make head or tail of something but if we persevere, we will make headway and things will become clearer in the end。