17000 bài tập tách từ đề thi thử môn Tiếng Anh có đáp án (Phần 3)

If my cousin an alarm, the thieves wouldn’t have broken into his house.

484/1620

If my cousin _____________ an alarm, the thieves wouldn’t have broken into his house.

installs

have installed

had installed

installed

Giải thích

Chọn C