Do you think it necessary for teachers to make friends with students .------I do .I think it is a good idea .A.Really B.Actually C.Usually为什么选B请详解,

Do you think it necessary for teachers to make friends with students .------I do .I think it is a good idea .
A.Really B.Actually C.Usually
为什么选B请详解,

问:你是否认为老师有必要同学生做朋友.
答:实际上我认为有必要,好主意..
A 的really是回答是真是假的肯定答案,而问的是是否有必要,所以不对.
B 的actually表示真的,实际上的,选在这里表示师生交朋友的必要性.
C 的usually表示的是动作的频率,与本文无关.