Question 43: He didn't try his best. He didn't make much progress.

        A. If he had tried his best, he can have made a lot of progress.

        B. If he had tried his best, he can't have made much progress.

        C. If he had tried his best, he couldn't have made much progress.

        D. If he had tried his best, he could have made a lot of progress.

Giải thích: Kiến thức: Câu điều kiện

Đề có : didn't try (Quá khứ đơn) => ĐK3 (Diễn tả tình huống không xảy ra trong quá khứ)

If + S + V (quá khứ hoàn thành) (had +Ved/V3, S + would/could/might +  have Ved/V3 => Đáp án D.

        A. If he had tried his best, he can have made a lot of progress.=> Sai ngữ pháp

        B. If he had tried his best, he can't have made much progress. => Sai ngữ pháp

        C. If he had tried his best, he couldn't have made much progress. => Sai nghĩa (Nếu anh ấy cố gắng, anh ấy không thể tiến bộ)

        D. If he had tried his best, he could have made a lot of progress.: Nếu anh ấy cố gắng, anh ấy có thể tiến bộ)  => Đúng