he has had trouble with cars and their owners
题目
he has had trouble with cars and their owners
里面的has had
是不是因为这里的人称是第三人称才加了has?
答案
has是助动词,没有实意,这里只用作引导一个现在完成时
had是实意动词,有的过去分词.
举一反三
已知函数f（x）=x，g（x）=alnx，a∈R．若曲线y=f（x）与曲线y=g（x）相交，且在交点处有相同的切线，求a的值和该切线方程．
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
最新试题
热门考点