5000 câu trắc nghiệm Tiếng Anh 9 có đáp án - Phần 111

Steel_____ with chromium to produce a no corrosive substance known as stainless steel.

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Steel_____ with chromium to produce a no corrosive substance known as stainless steel.

is combined

that is combined

combining

when combined

Giải thích

Chọn đáp án A