问题补充：
The number of students who took part in the competition last week more than 1500.
A. reach
B. were
C. is
D. was
答案：
A. reach
B. were
C. is
(答案→)D. was
解析：考查主谓一致。主语是The number of students，The number of+复数名词，作主语时，谓语动词用单数，排除A，B；且时间是last week，所以要用一般过去时态，选D。
