This camera is of good quality. If it ______ break down within the first year, we would replace it with a new one.
| A．would | B．might | C．could | D．should |
Mrs.Smith finds it hard to clear up the mess，as her children are always ________ whenever she tries to.
| A．in the way | B．on watch |
| C．in sight | D．on the line |
Before you pay a visit to a place of interest, look in your local library________a book about it.
| A．on | B．at | C．for | D．to |
Everything comes with ________ price；there is no such ________ thing as a free lunch in the world.
| A．a；a | B．the；/ | C．the；a | D．a；/ |
Many people agree that ________ knowledge of English is a must in ________ international trade today.
| A．the；an | B．a；/ | C．the；the | D．/；the |
In the market，vegetables are sold by ________ kilogram，I mean，by ________ weight.
| A．the；/ | B．/；/ | C．the；the | D．/；the |