When first to the market these new products in their company enjoyed a great success.A.

问题补充：

When first to the market, these new products in their company enjoyed a great success.

A. Introducing

B. introduced

C. to introduce

D. being introduced

答案：

A. Introducing

(答案→)B. introduced

C. to introduce

D. being introduced

解析：过去分词done表示与句中主语为逻辑上的动宾关系，表完成，没有一定的时间性。本题中，these new products与introduce之间是动宾关系，故应选B。本句含义，当他们公司的这些新产品第一次被介绍到市场上时，它们就享有很大的成功。