单项选择题
A. to avoid being eaten by arctic animals B. because fertilizer is not readily available C. to minimize exposure to the cold D. because unfrozen water supplies are very scarce
A. You use more energy if you walk rather than jog for the same amount of time. B. You use more energy if you jog rather than walk the same distance. C. You use the same amount of energy whether you jog or walk the same distance. D. You use the same amount of energy whether you jog or walk for the same amount of time.
A. New fashions in clothing are created for the commercial exploitation of women. B. The constant changes in women’s clothing reflect their strength of character. C. The fashion industry makes an important contribution to society. D. Fashion designers should not be encouraged since they are only welcomed by women.