B. was invented by the American Indians
C. has been known for hundreds of years
D. tends to be unhygienic
7. Bacteria which cause food to go bad ___.
A. cannot live in sunlight
B. are killed by drying
C. are in no way dependent on the water content
D. have their activity greatly reduced by drying
8. Nowadays vegetables are most commonly dried ___.
A. on horizontal cylinders
B. in hot-air chambers
C. in the sun and wind
D. using the open tray method
9. Dried foods ___.
A. are often packed in cans or frozen
B. are used by soldiers and climbers
C. need more storage space than soldiers usually have available
D. are much cheaper than canned or frozen products
10. Housewives like dried foods because they ___.
A. are quick to prepare
B. taste better
C. can be preserved by boiling in water
D. look fresh and appetizing when cooked
TEXT C
Please Recycle That Bobsled Run (大雪橇滑道)
11. Which of the following countries has not paid enough attention to the "green" issues?