IV. Complete each sentence with one suitable preposition.

1. My parents are sick, so I stay at home to take care ________ them.

2. Staying up late ________ night and getting up late ________ morning aren’t good ________ our health.

3. My sister tells me a lot ________ you.

4. Lan helps me ________ my homework.

5. The boy looks tired. What’s the matter ________ him?

6. I was worried ________ my next exam but my teacher smiled ________ me and said “Try your best. Don’t worry!”.