Trắc nghiệm Chuyên đề 3: Multiple choice (vocabulary and grammar) có đáp án

TheAstronauts Memorial Foundation honours all American astronauts have lost their lives on missions or in training.

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TheAstronauts Memorial Foundation honours all American astronauts                   have lost their lives on missions or in training.

whom

X

which

who

Giải thích

Chọn đáp án D