导线与电气元件间应采用（）连接、（）接、（）接、或（）接等。

在氧气、氢气、二氧化碳、大理石四种物质中，可用做高能原料的是______，可用于灭火的是______，可用于冶炼金属的是______，可用做建筑材料的是______．

阅读理解。

     Space travel is definitely bad for astronauts' bones, reducing their bone density(密度)

after only a month of weightlessness, according to French research published on Friday.

     Laurence Vico and his fellow workers at St Etienne University called for more research

into the effects of microgravity, after their study of 15 astronauts from the Russian MIR station

showed bone loss continued throughout space flights.

     "Bone loss was especially striking in four astronauts, " the scientists reported in the Lancet

Medical Journal.

     They measured the bone mineral density (BMD) of bones in the forearm(前臂) and

lower leg of the astronauts who had spent one to six months in space.

     The BMD loss was significant in the tibia(胫骨) of the lower leg, a weight-bearing bone,

but barely changed in the radius(桡骨) of the forearm. "Our results indicate the need to

investigate not only different bones, but also different areas of the same bone since not all

sites of the skeleton (骨架) are similarly affected by space conditions, " they added.

     Without gravity the body isn't bearing any weight so there is no need for calcium (钙)

which makes bones strong, and it becomes empty into the bloodstream.

     The research team suggested in future scientists should try to determine if the loss of bone

density was only on weight-bearing bones on longer flights, also the possible recovery after

returning to Earth.

1. French scientists did their research on Russian astronauts, because _______.

A. they only cared for the Russian astronauts

B. they were not interested in their own astronauts

C. the Russian government invited them to do their research

D. the Russian astronauts worked in space for a period of time

2. Scientists have found that _______.

A. the BMD loss may cause serious illness to astronauts

B. the BMD loss may cause some change in astronauts' bodies

C. astronauts shouldn't care about the BMD loss

D. astronauts should take some calcium before space travel

3. What cause the BMD loss to astronauts, according to this passage?

A. The food they eat in space.

B. The drinks they take in space.

C. The temperature in space.

D. The gravity in space.

4. In the third paragraph, the underlined word "striking" means ______.

A. unusual

B. simple

C. weak

D. slow

下列关于一般纳税人“营改增”政策的说法正确的有（）。

A.提供邮政普遍服务，适用税率为6%

B.接受的旅客运输服务，其进项税额可以从销项税中抵扣

C.境内单位提供适用零税率的应税服务，如果属于适用增值税一般计税方法的，实行免征增值税办法

D.纳税人提供适用不同税率或者征收率的应税服务，应当分别核算适用不同税率或者征收率的销售额；未分别核算的，从高适用税率

E.航空运输企业的销售额，不包括代收的机场建设费和代售其他航空运输企业客票而代收转付的价款

烧伤后皮肤红肿，有大小不一的水泡，创面红润潮湿，质较软，疼痛敏感，估计为（）。

A.度烧伤

B.浅Ⅱ度烧伤

C.深Ⅱ度烧伤

D.Ⅲ度烧伤

某公司2008年提取了公积金后的税后净利润为800万元，2009年的投资计划所需资金700万元，公司的目标资金结构为权益资金占60%、债务资金占40%。该公司采用剩余股利政策分配利润，则2008年可向投资者分红的数额为( )万元。

A．100
B．380
C．420
D．520