—What are you doing on your next day ___

题型:选择题

问题:

—What are you doing on your next day _______?        

—I want to have a good rest at home because I’m very tired these days.         [ ]

A. off          

B. on          

C. of          

D. up

考点:副词
题型:选择题

(16分)目前我国动车组列车常使用自动闭塞法行车,自动闭塞是通过信号机将行车区间划分为若干个闭塞分区,每个闭塞分区的首端设有信号灯,当闭塞分区有车辆占用或钢轨折断时信号灯显示红色(停车),后一个闭塞分区显示黄色(制动减速),其它闭塞分区显示绿色(正常运行)。假设动车制动时所受总阻力为重力的0.1倍,动车司机可视距离为450m,不考虑反应时间。(g取10m/s2)求:

(1)如果有车停在路轨而信号系统发生故障,司机看到停在路轨上的车才开始刹车,要使动车不发生追尾,则动车运行速度不得超过多少;

(2)如果动车设计运行速度为252km/h,则

①动车的制动距离;

②正常情况下,要使动车不发生追尾,每个闭塞分区至少多长。

题型:选择题

中度脱水时患儿失水量约为体重的( )

A.5%左右

B.10%以上

C.5%~100%

D.10%左右

E.5%以下

题型:选择题


The central problem of economics is to satisfy the people’s and nation’s wants. The problem we are faced with is that our (1) , here identified as money, are (2) . The only way we can resolve our (3) is to make choices. After looking at our resources, we must examine our list of (4) and identify the things we need (5) , those we can postpone, and (6) we cannot afford. As individuals, we face the central problem involved in economics — deciding just how to allocate our limited resources to provide ourselves with the greatest (7) of our wants.
Nations face the same problem. As a country’s population (8) , the need for more goods and services grows (9) . Resources necessary to production may increase, but there are (10) enough resources to satisfy the total desires of a (11) . Whether the budget meeting is taking place in the family living-room, in the conference room of the corporation (12) of directors, or in the chamber of the House of Representatives in Washington, the basic problem still exists. We need to find (13) of allocating limited resources in order to satisfy unlimited wants.
A short time ago, economists divided goods into two categories, free and economic. The former, like air and water, were in (14) abundance that economists had no concern about (15) of scarcity and what to do about it. Today many of these "free goods" are in (16) very expensive to use. Pollution has made clean air and water expensive for producers who have to filter their waste products, for consumers who ultimately pay for the producers’ extra costs, and (17) tax-payers who pay for the government’s involvement in cleaning the environment.
In the 1990s, almost all goods are (18) . Only by effort and money can they be (19) in the form people wish.
Meeting the needs of people and the demands from resources available leads to the basic activity of production. In trying to (20) unlimited wants from limited economic goods, production leads to new problems in economics.

题型:选择题

具有一定难度,需要学生努力克服,而又是力所能及的学习情境称为__________。

题型:选择题

对于提高邮政通信服务水平可以从以下( )着手改善。

A.服务网点

B.经办业务种类

C.服务方式

D.通邮条件

E.投递速度

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