I happened ____ this book before.A.having read B.to have read C.r_英语解答

I happened ____ this book before.A.having read B.to have read C.read D.reading

人气：307 ℃　时间：2019-08-23 10:55:13

解答

B
happen to do sth
固定搭配~
由于句子中有before,所以用have done的完成时~