Look,there are many -----students and -----teachers dancing

答案是A.
由girl,boy+名词 组成的复合名词变复数,只把后面的名词变成复数即可.
girl student---girl students
由woman,man +名词 组成的复合名词变复数,把woman,man和后面的名词都得变成复数形式.
woman teacher----women teachers
所以答案是A.