1:Questions and exercise are given by the computer ,which de
1:Questions and exercise are given by the computer ,which decides to move
the students ahead ,review an easier level,give more work on the same level.
A;either ,or B;whether or
2:you are in out ,it makes no different.
A;either ,or B;whether or
either ,or 也是多选一【一般多用于二选一】的意思,为什么不选它?