A：保留了高等的生物类群，淘汰了低等的生物类群
B：保留了新出现的物种，淘汰了低等的生物类群
C：保留了有益于人类的物种，淘汰了有害于人类的物种
D：保留了适应环境的物种，淘汰了不适应环境的物种
①市场能够通过价格信号，及时传递各类经济信息
②市场借助竞争机制，不断提高经济发展速度
③市场能够通过利益杠杆，促进技术进步和管理创新
④市场能够优化资源配置，实现全社会共同富裕
有关冬季我国北方和南方气温相差较大的原因，错误的表述是（ ）
下列句子中划横线词的活用情况，与例句中划横线词的用法相同的一项是（ ）
例句：沛公欲王关中
根据材料内容，选择正确答案。
There are 50 students in Class 8. Now they are doing a survey about how they spend their pocket money. Some spend it on books, and others spend it on visiting. What about you? Please read the form and answer the questions.
10%
55%
12%
13%
Buy some CDs and computer games.
Buy some snacks and drinks.
Buy some books in the bookshop.
Save it up and spend it traveling on holiday.
Buy some gifts for friends.
