1.If you didn't apply your  application in time,you won't be able to attend the entrance exams.

2..If you don't bring the identity card,you must not enter the exam room.

3..If we thought  over what we had done more carefully,we wouldn't feel sorry now.

4.The world wouldn't be destroy soon if people continue discharged the pollutants into the sea.

5.The world won't be threaten unless all the terrorist groups break down.

6.All endangered species will be come to an end if people don't reduce the chemical pollutants into the environment.

1. don't apply - won't be able to attend

2. don't bring - mustn't enter

3. thought- wouldn't feel

4. continue discharging - will destroy

5. will threaten - break

6. will come to an end - don't reduce