为了提高塑料大棚内蔬菜的产量,主要采取下列哪种措施? [ ] A.增加氧 B.升

题型:选择题

问题:

为了提高塑料大棚内蔬菜的产量,主要采取下列哪种措施? [ ]

A.增加氧

B.升高温度

C.适当增加二氧化碳

D.增加浇水次数

考点:光合作用
题型:选择题


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.

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下列图示实验操作中,正确的是[ ]

A.向试管中加锌粒

B.点燃另一酒精灯

C.检查装置的气密性

D.稀释浓硫酸

题型:选择题

X、Y、Z是3种短周期元素,其中X、Y位于同一主族,Y、Z处于同一周期。X原子的最外层电子数是其电子层数的3倍。Z原子的核外电子数比Y原子多1。下列说法正确的是(  )

A.元素X、Y的氢化物沸点Y的较高

B.Z元素最高价氧化物对应水化物的化学式可表示为HYO4

C.Y单质可在X的单质存在时燃烧产生化合物YX3

D.离子半径Z>Y

题型:选择题

人类的美好追求一直是()

A、建立公平、互惠、沟通的和谐社会

B、建立平等、互利、协调的和谐社会

C、建立有序、沟通、协调的和谐社会

D、建立平等、互助、协调的和谐社会

题型:选择题

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