is known to all China will be an and powerful country in 20 or 30 years’time.A. That; a

问题补充：

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

答案：

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。