When first _______ to the market, the products didn’t at Wap版

试题详情及答案解析

When first _______ to the market, the products didn’t attract much attention.

A．introducing	B．introduced
C．was introduced	D．being introduced

答案：B

试题分析: 句意：当首次被引入市场的时候，这些产品没有引起很多关注。此处是“连词+分词”结构，动词和句子主语products之间是被动关系，用过去分词，选B。
考点：考查非谓语动词