Answer:
1. DIDN'T you hear that the exam was changed to next week?
2. IT'S a very bad idea to get into a car if the driver has been drinking.
3. WHO'S having the party tonight?
4. Have you made a decision whether YOU ARE going to go to university or go backpacking in Europe?
5. Did you know that THEY'RE leaving the city for good?
Step-by-step explanation:
"It's" (means it is) and "Didn't" (means did not) and "Who's" (means who is) and "You" (means You obviously) lol and "They're" (means they are)
Hope this helped!