All the teachers and the students there are playing basketball on the playground .A. men;

问题补充：

All the teachers and the students there are playing basketball on the playground .

A. men; boys

B. men; boy

C. man; boy

D. man; boys

答案：

A. men; boys

(答案→)B. men; boy

C. man; boy

D. man; boys

解析：以两个名词构成的复合名词(前面的名词为man或woman除外)，有单数转换为复数时，一般把后面的名词变复数。 而当man, woman,和其它名词构成复合词时，其单复数以所修饰的名词的单复数而定，也就是说：如果变复数，两个词一起变复数。