of the students who took part in the military training is 450.
A. A number
B. A lot
C. A few
D. The number
网友回答
A. A number
B. A lot
C. A few
(答案→)D. The number
解析：考查主谓一致：根据后面的谓语is，可以判断选the number，因为the number of+可数名词的复数“…的数量”，谓语是单数形式，A. A number of+可数名词复数，谓语是复数，B.a lot of+可数名词复数，谓语是复数,C项，a few后面不加of，选D。