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

The annual production of household wastewater makes up over 30 percent of

505/1620

The annual production of household wastewater makes up over 30 percent of all wastewater _____________ into the environment in Vietnam.

be discharged

which discharged

was discharged

discharged

Giải thích

Chọn D