People sell their products advertisement in the newspaper.A. by putting anB. to put anC. b

问题补充：

People sell their products advertisement in the newspaper.

A. by putting an

B. to put an

C. by putting a

D. putting an

答案：

(答案→)A. by putting an

B. to put an

C. by putting a

D. putting an

解析：考查：介词by + doing 通过某种方式，advertisement 广告，它的发音以元音因素开头，所以一条广告用an advertisement，句意：人们卖产品通过在报纸上登广告的形式。所以选A。