In 1849, Walter Hunt, …………………. American inventor, patented a designthat served as the basis for modem safety pins.

In 1849, Walter Hunt, …………………. American inventor, patented a designthat served as the basis for modem safety pins.

A. an

B. he was an

C. who

D. was an

Câu trả lời là: A là đáp án đúng