There seems to be no one at home -Why not()at the back door A.to _英语解答

There seems to be no one at home -Why not()at the back door A.to try knocking B.to try to knock
C.trying to knock D.try knocking

人气：142 ℃　时间：2020-02-03 23:27:03

解答

C try doing 尝试