1. They, grow rice in tropical countries.
- Rice  is grown in tropical countries.
2. My uncle drives us to school.
- We  are driven by my uncle  to school.
3. As it rained heavily, they didn't go for a picnic.
> Since  it rained heavily, they didn't go for a picnic.
4. Hurry up, or you will miss the bus.
- If  you don't hurry up, you will miss the bus.
5. Please shut your mouth up. You make my class noisy.
- If you shut your mouth up, you won't make my class noisy.