When I was in primary school, I was told that the earth around the sun.
A. had travelled
B. would travel
C. travels
D. travelled
网友回答
A. had travelled
B. would travel
(答案→)C. travels
D. travelled
解析：考查时态。客观真理的动词形式即使在过去也是用一般式,因为这个动作是一个客观的持续,过去或者现在或者将来都不会改变。所以用的是现在式，选C。