It was in when I was here on business I found Chengdu so comfortable for people to li

问题补充：

It was in when I was here on business I found Chengdu so comfortable for people to live in.

A. when

B. before

C. that

D. which

答案：

A. when

B. before

(答案→)C. that

D. which

解析：考查强调句：强调句的结构是it is /was+被强调部分+that/who+…，这句话强调的是in when I was here on business，句意：就是在我在这儿做生意的我发现成都是适合人生活的好地方。选C。