“thanks” is polite when someone has done you a favour, but saying it too often is quite another thing.
A. Though saying
B. If saying
C. Saying
D. In spite of saying
网友回答
A. Though saying
B. If saying
(答案→)C. Saying
D. In spite of saying
解析：句意：当别人帮你忙的时候，说“谢谢”是礼貌的，但是说的太频繁又是另外一件事。这里第一个is是谓语，前面的是主语，用动名词做主语，所以选C。