15000 bài tập tách từ đề thi thử môn Tiếng Anh có đáp án (Phần 1)

For thousands of years, man has created sweet-smelling substances from wood, herbs and flowers and using them for perfumes or medicine. A. man B. sweet-smelling C. using them D. or

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For thousands of years, man has created sweet-smelling substances from wood, herbs and flowers and using them for perfumes or medicine.

man

sweet-smelling

using them

or

Giải thích

Đáp án C

Using them => used them