China's reform and opening has been going on for is like about 30 years now and it's really quite remarkable.
A. that
B. which
C. what
D. it
网友回答
A. that
B. which
(答案→)C. what
D. it
解析：答案：C 考查名词性从句。句意：中国的改革开放现在已经进行了大约三十年，效果非常明显。 is like about 30 years now是介词for的宾语，该部分缺少主语，所以选起双重作用的what。