题干

按一对夫妇一两个孩子计算,人口学家统计和预测,墨西哥等发展中国家的人口翻一番大约20—40年,美国需要40—80年,瑞典人口将会相对稳定,德国人口将减少。预测人口的这种增减动态主要决定于(  )

A:种群性别比例

B:种群数量和密度

C:种群年龄结构

D:出生率和死亡率

上一题 下一题 0.0难度 选择题 更新时间:2019-10-02 12:44:02

答案(点此获取答案解析)

B

同类题1

一带一路”(丝绸之路经济带和21世纪海上丝绸之路)建设是新形势下我国对外开放的重大战略。阅读材料,回答问题。

  

材料二  四川作为内陆省份,处于陆上丝绸之路和海上丝绸之路的交汇点,是沟通中亚南亚东南亚的重要交通走廊,拥有通往欧洲的快铁大通 道,国际航线数量居中国西部第一。四川电力设备、电子信息、服装纺织、农机农资、能源综合利用等产业基础较好、具有特色,但钢铁、水泥、化工等行业存在富 余产能。借“一带一路”建设之势,四川力争3年内对沿 线国家的贸易从200亿美元扩至300亿美元,集中突破20个对外投资项目;在轨道交通、航空航天、现代金融、现代物流等领 域打造一批新的千亿产业集群,着力培育信息服务、跨境电子商务、服 务外包等新型服务贸易。

材料三  “一带一路”既是经贸之路,也是文化之路。某校高二(1)班同学围绕“四川省如何增进与‘一带一路’沿线国家的文化交流”展开讨论,提出了建议(见表1)。

建议

依据

合作考证对丝绸之路历史文化遗产的保护

示例:文化遗产没,是一个国家和民族历史文化成就的重要标准,是人类共同的文明财富

联合打造具有丝绸之路特色的国际精品旅游线路和旅游战略


建设国际认知度高的文化网络平台


注入时代精神,采用动漫,微电影等流行方式,讲好四川故事


积极参与中国政府与沿线国家互办的文化年,艺术节,电影周等活动


同类题4

根据短文内容,选择正确答案。

    Open today's newspaper. What do you see? Ads! Look through a magazine. More Ads! Turn on TV, still more ads! Everywhere you look, someone has something to tell. Here are some ways ads get us to buy.

    Some ads use famous people. Stars are paid to sell a product. Think about it. Do they really know about medicine? Do they know about soft drink? These people may be famous. But they may not know about what they are selling.

    Some ads make you think you're getting the word of an expert. They say, "Doctor said." A man in a white coat comes on TV. He looks nice. "I use bright and white," He says. This man looks like a doctor. But he is an actor. He has been paid to sell this product.

    Does soap have anything to do with a pretty child? Not much. But ads may show their product with something nice such as the sun, the flowers and so on. Such an ad is about feelings rather than facts.

    Ads are full of strong words, and words like "new" and "improved" have power. They can help a produce sell. The soap may be called "Spring Rain". A car may be called "Tiger". Strong words work on our feelings.

    Some ads make promise. But can they keep them? No.

    Some ads use our fear of being too late. "Buy now!" They say, "Selling ends soon." Check to see if this is true. Don't hurry. Take time to think.

    All ads hope we will buy something, do something, or think in a certain way. Know what ads are doing. Ask questions to yourself. Don't let their words and pictures fool you.