參考答案:
1.Though we may enjoy reading about the lives of others,it is extremely doubtful whether we would equally enjoy reading about ourselves.
2.It has always been a mystery to me why city dwellers,who appreciate all these things,obstinately pretend that they would prefer to live in the country.
3.It was nice seeing you.
4.It's necessary learning the new technology.
5.It's no use trying to open the door.