1. If they (not /study).............hard, they will fail their final examination.
2. Don't forget (turn)............off the faucets when you go out.
3. My brother is used to (wash).... his clothes in the morning.
4. Tom (write)............. this letter three hours
5. Nam enjoys (work)................with children.
1. If they (do not study).............hard, they will fail their final examination.
2. Don't forget (to turn)............off the faucets when you go out.
3. My brother is used to (washing).... his clothes in the morning.
4. Tom (has written)............. this letter three hours
5. Nam enjoys (working)................with children.