单选题 Statistics ______ his most difficult subject and they are all worried that he won't pass the test.
A. is B. are C. was D. were

【正确答案】 A
【答案解析】以-s结尾的名词，如maths，physics，statistics等表示学科时，谓语通常用单数形式。
译文：统计学对他来说是最难的学科，他们都担心他通不过考试。