问题补充:
The Diaoyu islands have been part of Chinas territory since ancient times, as important fishing grounds of Taiwan.
A. served
B. to serve
C. serving
D. having served
答案:
A. served
B. to serve
(答案→)C. serving
D. having served
解析:C 考察非谓语动词。句义:钓鱼岛作为台湾的重要渔场,自古以来就是中国的领土。分析句子结构可知,空格处做伴随状语,且和主语是逻辑上的主动关系,故用现在分词做状语,表示主动关系。故C正确。