Réponse :

1- All the students should get good marks.

2- All the students should have gotten good marks.

3- I should have left earlier than seven.

4- I should leave earlier than seven.

5- Why should I have not told him the truth.

6- Why should I not tell him the truth.

7- Everything should be alright.

8- Everything should have been alright.

9- It should work.

10-It should have worked.

hope this helps, bonne chance :)