Choose the best answers to complete the following sentences, to identify one mistake or to choose the best rewritten sentences.

Câu hỏi

There's someone_______on the door. Come to see who he/she is.

A. knock

B. knocking

C. to knock

D. having knocked

Đáp án
B. knocking

Câu hỏi thuộc Bài tập:

2023- GRAMMAR Test 1