It is silly you to give up to America for further study.
A. for, to go
B. for, going
C. of, to go
D. of, going
网友回答
A. for, to go
B. for, going
C. of, to go
(答案→)D. of, going
解析：for为了表示目的原因等，of ……的表示属性所有等，give up doing sth放弃做某事，根据题意选D。放弃去美国进修的机会，你太傻了。