题干

已知正数x,y满足x+2y=1,则
1
x
+
1
y
的最小值为(   )

A:22

B:42

C:3+22

D:3+42

上一题 下一题 0.0难度 选择题 更新时间:2019-08-28 07:37:54

答案(点此获取答案解析)

C

同类题2

一个国家的发展强大与海洋的开发利用有着密不可分的关系。阅读材料,回答问题。

材料一:中国古代海外贸易历史悠久,它是随着中国社会经济的发展和造船航海业的进步而不断发展的,成为古代中国对外经济联系的一个主要梁道。

——搜狗百科·中国古代海外贸易

材料二:起源于海洋文明的西方国家很早就重视海洋的意义。几百年来,萄萄牙、西班牙、荷兰、英国乃至今天的美国在世界上的优势力量都是以海权为基础的。

——《科普百家论坛:海军武器实录》

材料三:孙中山说:“中国海权一日不兴,则国基一日不宁。”“争太平洋之海权,即争太平洋之门户权。人方以我为争(意为别国以我国为争夺瓜分的对象),岂置之不问。”孙中山面对旧中国的形势,从民族存亡和民生的角度关注海洋,在《实业计划自序》中说:“操之在我则存,操之在人则亡。”

——杨金森、范中义《中国海防史》

材料四:有的学者从中国面临20世纪80年代世界第二次重大产业梯度转移出发,提出只有采取率先加快沿海地区对外开放的战略,才能抓住这个难得的机遇。“因为内地无论从区位上、与海外的联系上还是从工业基础上、科学技术水平上、劳动者的素质上,都与沿海存在差距。能较快扩大开放,转换机制,吸引海外资金和技术,吸收和借鉴外国一切反映现代社会化生产规律的先进经营方式、管理方法、率先接收东亚地区第二次重大产业样度转移的,还是沿海地区。”

——夏禹龙《加速发展、达到共同富裕的捷径》

同类题3

任务型阅读

    Happiness is not the absence of problems____Here are a few reminders to help motivate you when you need it most:

    ⒈Pain is part of growing.

    When times are tough, remind yourself that no pain comes without a purpose____ Every great success requires some type of worthy struggle to get there. Good things take time. Everything is going to come together; maybe not immediately, but eventually.

    ⒉____

    Every time it rains, it stops raining. Every time you get hurt, you heal. After darkness there is always light. So if things are good right now, enjoy it. It won't last forever. If things are bad, don't worry because it won't last forever either.

    ⒊Worrying and complaining changes nothing.

    ____ It's always better to attempt to do something great and fail than to attempt to do nothing and succeed. It's not over if you've lost; it's over when you do nothing but complain about it. If you believe in something, keep trying. Don't let the shadows of the past darken the doorstep of your future.

    ⒋Your scars are symbols of your strength.

    Never be ashamed of the scars life has left you with. A scar means the hurt is over and the wound is closed. It means you overcame the pain, learned a lesson, grew stronger, and moved forward____

A. Everything in life is temporary (暂时的).

B. But it is the ability to deal with them.

C. Rarely do people do things because of you.

D. A scar is the sign of a success to be proud of.

E. Those who complain the most, accomplish the least.

F. Move on from what hurt you, but never forget what it taught you.

G. Change because it makes you a better person and leads you to a brighter future.