1. Mary looks happy as she has just got good marks.
2. Because a computer can be used for various purpose, it becomes very popular today.
3. The burglars were able to break into his house as he has forgot to lock one of the windows.
4. Because the exercise is not eáy, i shall have to consult my teacher.
5. I didn't come in time since there was a traffic jam.
6. Because the teacher is sick, we will have no class 2morrow.
7. He studies maths very hard as he wants to become a teacher of maths.
8. Peter was worried since Mary was late.
9. Because the TV program was uninteresting, the went to bed early.
10. I couldn't answer all the oral questions well since i felt too nervous.
* because=as=since: vì