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

问题描述:

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

B ,因为happen to 是偶然的意思,全句解释为我碰巧以前读过这本书
以前读了要有完成时所以CD不对

选择B,因为根据题目中的before一词,得知“我”  已经  (完成时)读过这本书,Be happen to do 是固定句式,意思是碰巧做过某事。综合以上,选B

B

选择B,happened to do 固定短语搭配。
I happened to have read this book before我之前碰巧有读过这本书

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~

b
happen to do sth,这里又是完成状态,所以用完成时

1.happen to do
2.before——所以是过去式或过去完成时。此句的汉语意思“曾经读过 ”对现在有影响,所以用完成时