题目

Except for a few times, Americans are not big present-givers. There's no exchange of presents among business people, and if one American tries to give another a present, it may look like that he wants to bribe (贿赂) him. Americans have learned that in some other countries people like to give presents to others, but among ourselves we don't see the need for presents. Even friends may never exchange presents. When I go to foreign countries, I try to bring back little things for close friends, but nobody would feel unhappy if I didn't. I don't often remember a friend's birthday, and few peopl我国海南岛，森林植被繁茂，动物种类众多，形成这种格局的主要因素是（  ）A．水分和温度B．水分和大气中二氧化碳C．水分和土壤养分D．阳光和温度