2000 câu trắc nghiệm tổng hợp Tiếng Anh 2025 có đáp án (Phần 28)

What does the word "these" in the second paragraph refer to?

47/80

What does the word "these" in the second paragraph refer to?

chemical wastes

poisons

factories

new chemicals

Giải thích

Chọn A

Thông tin: Factories that make or use chemicals always have chemical wastes. These are often poisonous, and they also stay in the environment.