等长收缩是（） A.运动时肌张力基本恒定 B.收缩时肌肉长度改变，产生关节活动 C.

货物点到点成本的计算公式为( )。

A．某批货物点到点运输成本=发到作业量×发到作业单位变动支出+中转作业量×中转作业单位变动支出+S(分类的运行作业量×运行作业单位变动支出)
B．某批货物点到点运输成本=发到作业量×发到作业单位变动支出+中转作业量×中转作业单位变动支出+分类的运行作业量×运行作业单位变动支出
C．某批货物点到点运输成本=发到作业量×(发到作业单位变动支出+中转作业单位变动支出+运行作业单位变动支出)
D．某批货物点到点运输成本=S(发到作业量+中转作业量+分类的运行作业量)×运行作业单位变动支出

中央国家机关与地方国家机关是以( )为标准划分的

A．国家机构的性质

B．国家机构的历史

C．国家机构和行使权力的属性

D．国家机构行使权力的效力范围

手术人员手臂刷洗消毒后，手臂应保持的姿势是()。

A．手臂向上高举

B．手臂自然下垂

C．胸前拱手姿势

D．手臂向前伸

E．双手放置背后

阅读理解。

     Forget chip fat, sugar cane or rapeseed oil-the latest source of biofuel could be watermelons.

     Scientists have discovered that the fruit is a great source of sugar that can be readily distilled (蒸馏) into

alcohol to power cars and farm machinery.

     And because sellers reject 360,000 tons of" substandard"fruit annually in America alone they could be used

as an economical way to make fuel.

     The waste from US growers could produce nearly two million gallons( nine million litres) of biofuel per

year.

     In the study, researchers at the United States Department of Agriculture set out to determine the biofuel

potential of juice from rejected watermelons-those not sold due to cosmetic imperfec tions, and currently

ploughed back into the field.

     About a fifth of each annual watermelon crop is left in the field because of surface blemishes (瑕疵) or

because they are missha pen.

     Dr Wayne Fish, who led the team, found that 50 per cent of the fruit was fermentable(可发酵的) into

alcohol which could provide valuable fuel.

     "We've shown that the juice of these melons is a source of readily fermentable sugars, representing an

unexploited raw material for alcohol biofuel production," he said.

     The study, published in the journal Biotechnology for biofuels, discovered that watermelons could produce

around 20 gallons of fuel per acre from fruit that otherwise would go to waste.

     Production of biofuels has been targeted by western govern ments as a way to support renewable energy

targets.

     The European Union has a target for 2010 that 5.75 per cent of transport fuels should come from biological

sources, but the target is unlikely to be met.

     The British government's Renewable Transport Fuel Obligation requires five per cent of the fuel sold at the

pump by 2010 to be biofuel.

1. The passage mainly tells us _____.

A. western countries aim at producing biofuels

B. watermelons could be used to make fuel

C. the advantages of fuel made from watermelons

D. watermelon juice will be the largest source of renewable en ergy

2. Which of the following is NOT the reason why so many water melons are deserted in America each year?

A. They are substandard.

B. They are imperfect.

C. They are misshapen.

D. They are oversupplied.

3. It can be learned from the text that _____.

A. sellers in the world throw away 360,000 tons of watermelons every year

B. about two gallons of fuel could be made from rejected fruit per acre

C. half of the watermelons were fermentable into alcohol to provide energy

D. five per cent of fuel is required to be biofuel from watermel ons by 2010 in Britain

4. The underlined word " cosmetic" in Paragraph 5 probably means _____.

A. inside

B. flavor

C. surface

D. freshness

如图所示是现代家庭经常使用的自动升降衣架的结构示意图，它可以很方便晾起洗好的衣服，取下晒干的衣服，其实就是通过一些简单机械的组合来实现此功能。图中动滑轮有__________个，此装置      （填“能”或“不能”）改变动力的方向。