1．At first Sally was frightened of planes，but two years later，flying to other countries on business is her main business.
2．I must apologise(道歉) for not being able to meet you.
3．I have arranged that one of my staff will meet you at the airport.
4．The basic causes are unknown(未知的)，although certain conditions that may lead to cancer have been discovered.
5．The school has only been open for six months，so it's too early to evaluate its success.
6．Follow the footpath and you'll eventually hit the road.
7．After all，I call someone my cousin if she and I have a common ancestor(祖先)．
8．His heroic deeds(行为) were celebrated in every corner of India.
9．Within this lecture(演讲) I cannot pretend to deal adequately with dreams.
10．Since the roads are very bad，the journey took us a long time.
