1.
He spent most of his time of summuer holiday on Internet.
或者
Surfing the Internet occupied most of his summer holiday.
2.
The girl who used to a model has become a actor.
3.
If you are willing to make several conversations with her ,you will find that she is not as bad as what you have thinked of before.
4.
I decided to find a place for rest as the day was getting darker.(过去时比较好)
5.
Although you can't make great progress on calligraphy in such a short time, you should keep practicing.