自然吸气的四冲程内燃机换气损失功指（）A.膨胀损失功、机械损失功和附件损失功 B.膨

生态系统中营养物质再循环在人为状态下进行的途径是( )。

A．物质由动物排泄返回环境

B．人类利用化石燃料生产化肥，用海水制淡水及对金属的利用

C．风化和侵蚀过程加上水循环携带营养元素进入生态系统

D．物质通过微生物分解有机物碎屑返回环境

为了提高土地肥力，满足作物生长的需求所采取的人为干预措施是【 】

A．土地变更

B．土地改良

C．土地规划

D．土地开发

假定城镇土地使用税每平方米税额为5元，下列中处理正确的是( )。

A．村民李某在本村开的旅社占地2000平方米，应纳税额10000元
B．北京市法院占用的土地面积为40000平方米，应纳税额200000元
C．化工厂厂区内绿化用地800平方米，应纳税额4000元
D．某非营利性医疗机构占地1000平方米，应纳税额5000元

According to ancient records, the first tax that the government of Selea imposed on a basic commodity was a tax of two centima coins on every jar of cooking oil sold in Selea. Tax records show that despite a stable population and strict enforcement of tax laws, revenues from the oil tax declined steeply over the first two years that the tax was in effect.
Which of the following, if true, most helps to explain the decline in Selean oil-tax revenues

A．During the decade following the implementation of the tax, the average household income in Selea rose steadily.

B．Two years after implementing the tax on cooking oil, the Selean government began to implement taxes on numerous other basic commodities.

C．Jars of cooking oil were traditionally bought as wedding gifts in Selea at the time the tax Went into effect, and gifts of cooking oil increased after the implementation of the tax.

D．After the tax was imposed, Selean merchants began selling cooking oil in larger jars than before.

E．(E) Few Selean households began to produce their own cooking oil after the tax was imposed.

窗扇与窗框的密闭处理的方法有（）

A.贴缝式

B.密闭法

C.内嵌式

D.黏结法

E.垫缝式