题目

An idiom (习语）is a phrase that we can’ t understand from the meaning of each word. For example, if an American boy asks his mum what’s for dinner tomorrow, she may say, “I’ll play it by ear.” That means she doesn’t have plans for dinner and she will decide later.“Play it by ear” used to mean playing music without using the sheet music (活页乐谱），but now it’s different.There are many idioms in English. If you learn to use them, your English will be much more colorful.Have you ever heard the idiom “He bought the farm”? It means “He died Do you know how it bec纪实片《穹顶之下》引起了全社会对环境污染的广泛关注。PM2.5是造成雾霾的主要因素，呼吸道对其几乎没有净化作用。下列说法正确的是A. PM2.5通过扩散作用由外界空气进入肺泡B．雾霾天气里，人呼出的气体中二氧化碳的含量高于氧气C．减少雾霾改善窒气质量的根本措施是大规模植树造林D．PM2.5吸人人体后，干扰肺部的气体交换，引发哮喘等疾病