[填空题]You should be careful when_________ (cross) the street in big cities.

[单项选择]Be careful when you cross this very busy street. If not, you may ______ run over by a car.
A. have
B. get
C. become
D. turn

[填空题]You should be careful when ______ (cross) the street in big cities.

[单项选择]Do be careful when you cross the street, ______ you
A. don’t
B. aren’t
C. will
D. must

[填空题]You should have careful（）(consider) before you act.

[填空题]

During the summer you should be even more careful than usual of the foods you prepare. Foods spoil faster in hot weather than in cold weather. When you are shopping, buy frozen and refrigerated foods last. Don’t make long stops on the way home, because frozen roods could become soft or warm. Using insulated bags helps keep food cool until you can get home. Milk and milk products should be refrigerated immediately. When camping or at some time when refrigeration isn’t available, use special dry foods. Don’t leave foods in a hot car or beach bag. Picnic favorites like meat, chicken, and egg salad should be kept in a cooler place. Above all, if a food doesn’t seem to be normal in order or appearance, throw it away immediately. Don’t taste it.

What kind of foods should you buy last
You should buy frozen and（）last.

[填空题]Be careful while (cross)（）the street.

[填空题]You should have careful ______ (consider) before you act.

[判断题]Dr. Wilson suggests that Wang should extend his stay at the university.

[填空题]Be careful where you put this.

[单项选择]You can’t be too careful when you drive a car on the icy road.
A. 在结冰的路面上驾车无需过于小心谨慎。
B. 在结冰的路面上驾车不小心是不行的。
C. 在结冰的路面上驾车，怎么小心都不为过。
D. 在结冰的路面上驾车更应该小心谨慎。

[单项选择]You cannot be______careful when you drive a car.
A. very
B. so
C. too
D. enough