题目内容：

who will be our class teacher next term do you know
do you know --------- ------------ be our class teacher next term

优质解答

do you know ----who----- ---will--------- be our class teacher next term

追问：

什么时候连接词用if/whether

追答：

是否 的意思时，如 I don't know if it is right. 我不知道它是否是对的。