Bộ 10 đề ôn thi học sinh giỏi Tiếng anh 9 năm 2023 có đáp án (Đề 4)

(62) ________ the need arises, they can buy the eggs and larvae of these natural predators and introduce them into their crop fields.

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(62) ________ the need arises, they can buy the eggs and larvae of these natural predators and introduce them into their crop fields.

Then

If

Because

Though

Giải thích

Chọn B