of the students who took part in the military training is 450.A. A number B. A lot C. Lot

问题补充：

of the students who took part in the military training is 450.

A. A number

B. A lot

C. Lots

D. The number

答案：

A. A number

B. A lot

C. Lots

(答案→)D. The number

解析：考查固定结构。A number of许多，大量（修饰可数名词复数）做主语，谓语动词用复数；a lot of/lots修饰可数名词复数或者不可数名词，修饰可数名词复数时，做主语，谓语动词用复数。The number of指…的数量；作主语，谓语动词用单数形式。句意：参加军训的学生的数量超过了450.