1/ Mary couldn’t ......................... to the meeting this morning.
A. come B. to come C. coming D.came
2/ Jack should ....................... harder.
A. studies B. to study C. study D. studying
3/ The whole team must ...... together to win the game.
A. worked B. to work C. work D. working
4/ To stay alive, people ................... breathe oxygen.
A. must/have to B. must not C. dont have to
5/ My room is a mess, but I .............. clean it before I go out tonight. I can do it in the morning.