Unit 1
　　1. ___________ (直到天黑了) that she realized it was too late to go home.
　　2. Color and sex are not relevant to _______________________ (一个人是否适合这个职位).
　　3. Corn originated in the New World and thus ________________ ( 在欧洲不为人所知 ) until Columbus found it being cultivated in Cuba.
　　4. I don't mind your delaying making the decision _________________(只要不是太晚).
　　5. There are few electronic applications _________________________ (更容易引起有关未来就业机会的恐惧) .

　　Unit 1答案解析：
　　1. It was not until dark that
　　2. whether a person is suitable for the job
　　3. was not known in Europe
　　4. as long as it is not too late
　　5. more likely to raise fears concerning future job opportunities
　　respecting, regarding , concerning: I wrote a letter respecting / regarding / concerning my daughter's school examinations.
　　provided = if : We will pay you the bonus provided the job is completed on time.
　　supposing. Supposing it rains tomorrow, what will you do?