Bộ 10 đề ôn thi học sinh giỏi Tiếng anh lớp 9 năm 2023 có đáp án (Đề 6)

What is the main topic of the passage? A. The changing pollutants in the atmosphere. B. The decreasing pollution of the atmosphere. C. Hydroxyl’s influence on the atmosphere. D. The oxygena

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What is the main topic of the passage?

The changing pollutants in the atmosphere.

The decreasing pollution of the atmosphere.

Hydroxyl’s influence on the atmosphere.

The oxygenation of the atmosphere.

Giải thích

Chọn A