1_____there is no rain,farming is difficult or impossible

1_____education is the instruction that occurs when the instructor and students are separated by distance or time,or both

Which do you think is ________, health or wealth？

_______________will not continue if an ongoing operation is changed or deletedA、

29．__________ when you are on the bus or bike．

软盘的第______磁道一旦损坏，该盘就不能使用了。

软盘的第（）磁道最重要，一旦损坏，该磁盘就不能使用了。

软盘上第()磁道最重要，一旦破坏，该盘就不能使用了。

软盘上第( )磁道最重要，一旦损坏，该盘就不能使用了。

Which do you think is _________________important, health or wealth?

Duty is an act or a course of action that people __________you to take by social customs, law or religion.

当软盘感染病毒,用各种清除病毒软件都不能清除病毒时,则应该对此软盘______。