（1）若|2x-8|+|y-6|=0，求2x-y的值； （2）已知有理数m、n互

International free trade occurs when there are no barriers to trade. Countries can get a lot of benefits from free trade. (31) , all countries choose to adopt protection policies to some extent In this essay, I will give (32) of the arguments in favour of world free trade, describe the methods for the trade protection policies (33) countries erect to protect domestic industries and give the arguments which can be put (34) to justify protectionist policies.
Tariffs are taxes on (35) products. Sometimes, tariffs are known (36) imports duties and customs duties. They can be used (37) raise revenue. But, they are usually used to (38) imports and also to help domestic producers. The effect of imposing (39) tariff is to raise price for domestic consumers, and some consumers will switch consumption (40) imported goods to domestically produced substitutes. (41) are two types of tariffs. One is percentage taxes, it is based on
percentage of value of goods. (42) one is specific (fixed sum taxes), it is based on a fixed tax (43) unit or weight. Quota is a limit on the supply of goods or services. It can be imposed on exports. The domestic market share will increase because of (44) a limit on the quantity of imported goods. However, the price of protected goods will also rise because a quota is to reduce supply. Voluntary export restraint or restriction (45) similar to a quota, but this time the limit on imports arises from a voluntary agreement (46) the exporting and importing countries. For example, the UK had an agreement with Japanese car (47) that they should not take (48) than 10 percent of the UK car market. Exchange control means that a government control on foreign currency controls importers access to foreign currency. This is a (49) which was used by a number of European countries, (50) the UK, in the 1960s and 1970s and is still found in some developing countries.

下列有关作业成本法的表述正确的有( )。

A．作业成本法提高了会计数据对管理控制的有用性

B．在极易产生成本扭曲并且准确的成本信息具有较大价值时，适宜采用作业成本法

C．作业成本法提供了了解产品作业过程的途径，使管理人员知道成本是如何发生的

D．从目前的情况看，作业成本法没有普遍意义，不会被广泛采用

继发于支气管阻塞的支气管扩张好发部位为（）

A.右肺上叶

B.右肺中叶

C.右肺下叶

D.左肺上叶

E.左肺下叶

木块的密度是0.6g/cm³，冰块的密度是0.9g/cm³，若它们的体积相等，都漂浮在水面上，则木块受到的浮力______冰块受到的浮力，木块露出水面的体积______冰块露出水面的体积．（选填“大于”“小于”“等于”）

某饱和软黏土边坡已出现明显的变形迹象，可以认为在ψ_u=0整体圆弧法计算中，其稳定性系数k₁=1.0。假设有关参数如下：下滑部分W₁的截面积为30.2 m²，力臂d₁=3.2 m，滑体平均重度为17 kN/m³；为确保边坡安全，在坡脚进行了反压，反压体W₃的截面积为9 m²，力臂d₃=3.0 m，重度20 kN/m³。在其他参数不变的情况下，反压后边坡的稳定系数k₂接近（）

A．(A) 1.15

B．(B) 1.26

C．(C) 1.33

D．(D) 1.59