Aidez moi s'il vous plait, c'est un devoir a rendre pour lundi, et je bloque sur 2 exercices.. :( Sa fait 2 heures et demi que j'y suis dessus et je n'y arrive

exercise1 
1-can..............can't
2-can
3-can
4-can't..........can
5-can...........can't 
exercice 2 
2-you have already visited...................
3-he has seen ..............he has never been........
4-we have gone...............we have already seen
5-they have lived ................ they have been ..........