is known to all, China will be an and powerful country in 20 or 30 years’time.
A. That; advancing
B. This; advanced
C. As; advanced
D. It; advancing
网友回答
A. That; advancing
B. This; advanced
(答案→)C. As; advanced
D. It; advancing
解析：句意，众所周知，中国在20年或是30年之内，将会成为一个发达国家。 As is known to all 是固定搭配,众所周知的意思；advanced 意为发达的，而advancing意为发展中的，故选C。