In America, many people waste a lot of food _____ in Africa people haven’t enough to eat.
| A．however | B．although | C．as | D．while |
-- Do you think it's a good idea to make friends with your students?
-- _____ , I do. I think it's a great idea.
| A．Really | B．Obviously | C．Actually | D．Generally |
- I wonder how much you charge for your services.
-- The first two are freethe third costs $30.
| A． | while | B． | until | C． | when | D． | before |
We can never expect____ bluer sky unless we create_____less polluted world.（）
| A． | a; a | B． | a; the |
| C． | the; a | D． | the; the |
As the light turned green, I stood for a moment, not _________, and asked myself what I was going to do.
A. moved B moving C. to move D. being moved
There is nothing more I can try you to stay, so I wish you good luch.
| A．being persuaded | B．persuading | C．to be persuaded | D．to persuade |