Ex1.
1. My dad has worked in a company since 2000
2. Those students aren't old enough to drive motorbikes
Ex2.
1. Tom wasn't hard- working so he couldn't get good marks.
2. It is dangerous to swim across this river
3. The blue dictionary isn't as expensive as the red dictionary
4. I haven't seen him since 1995
5. They hate cooking meals
6. Lan is as pretty as her sister
Ex3.
Dear Mom and Dad,
I'm having a wonderful time in Ha Long Bay.
The weather is very lovely and the beach and the islands look very beautiful.
Yesterday, I went shopping at Hon Gai Town.
I'm going to visit Dau Go Cave tomorrow.
I'm going to take photographs there.
See you soon.
Love,
Linda.