单项选择题
A.大家在生活中都可能交到朋友,只是有人没有交到知心朋友。 B.人人一生中都会交到朋友,只有他没有交到好朋友。 C.每个人在生活中都交过朋友,只是有的人交了好朋友。 D.并不是每个人在生活中都会交到朋友,他就没交到好的。
A.Climatic conditions. B.The length of days and nights. C.Ocean tides. D.Geographic boundaries.
A.they have developed advanced forms of transportation. B.they have learned how to process seawater for drinking. C.their body temperature can vary considerably. D.their shelter and clothing help them adapt to the environment.