i saw a boy.the boy was playing with a cat.
问题描述:
i saw a boy.the boy was playing with a cat.
i saw a boy _ _ _ _ a cat
合并为一句
答
如果4条短线代表每条线上一个单词的话,那就得who was playing with;如果不限制单词数量的话,用playing with就可以了