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

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. What; advanced

C. As; advanced

D. It; advanced

答案：

A. That; advancing

B. What; advanced

(答案→)C. As; advanced

D. It; advanced

解析：考查非限制性定语从句，As 正如，指后半句话的含义，句意：正如我们所知道的那样，中国在二十或三十年代是一个先进的强有力的国家。所以选C。