Einstein’s Theory of Relativity was so that few people could understand it at that time.
A. controversial
B. religious
C. abstract
D. contradictory
网友回答
A. controversial
B. religious
(答案→)C. abstract
D. contradictory
解析：考察形容词词义辨析。A有争议的；B虔诚的，宗教的；C抽象的；D矛盾的；句意：爱因斯坦的相对论是如此的抽象以至于在那个时候很少有人能够理解它。根据句意说明C正确。