Tom is a teacher , but Jim isn't . That is to say_______________.
A neither of them is a teacher
B both of them are not teachers
C either of them is a teacher
D all of them are not teachers

原因？谢谢。

Tom is a teacher , but Jim isn't . That is to say___B___.
A neither of them is a teacher
B both of them are not teachers
C either of them is a teacher
D all of them are not teachers
关于both,all都是部分否定,不管both not还是not both,这里选B更好，因为根据题目的意思，Tom是一个老师，Jim并不是，是强调两个人不都是老师呢还是两个人都有不是老师的可能性呢？
B表示，他们两个并不都是老师。
C表示，他们都有可能不是老师（而Tom已经没有不是老师的可能了）
所以B更好。