你认为一种传染病的流行必须具备缺一不可的哪三个环节? ____请你对如何预防非典性型肺炎提出自己的意见。____
To our surprise, all the l____ on the tree were eaten up by the cow soon.
下列句子中加横线的词语用得恰当的一句是( )。
选出与划线单词意思相对的词语。
I like this cat. I don't like one.( )