为了实现人类移居月球的梦想,北京航空航天大学建立了“月宫一号”人工密闭舱生态系统

题型:实验题

问题:

为了实现人类移居月球的梦想,北京航空航天大学建立了“月宫一号”人工密闭舱生态系统,人类生活所需的物质,可以在该系统内循环再生。下图是 “月宫一号”密闭舱内的碳循环示意图(注:①和②表示气体),请根据图回答:

(1)密闭舱内的实验人员属于该生态系统中的     者。

(2)人在密闭舱内能够生存,主要是由于绿色植物通过       作用为人类提供食物和[①]       

(3)[②]是植物光合作用的原料之一,它主要来自密闭舱内的生物通过呼吸作用,在细胞质中的          内产生。

(4)一般地说,生态系统中生物种类和数目越多,生态系统的结构越        (填“简单”或“复杂”),其自我调节能力就越        

考点:生态系统的概念和组成食物链和食物网生态系统的多样性生态系统的自动调节能力生态系统的功能
题型:实验题

Not everyone goes to university after high school graduation. Some work, others join the army and an increasing number worldwide are taking a “gap year” to travel or do community service in their own countries or abroad. They are studying sharks off the Australian coast, building schools in Mexico and learning Spanish or Italian.

The concept of a gap year may not be new, but the recent surge (涌现) of interest certainly is.  Some students are putting off admissions. Others, who don’t get into the college of their choice, are taking a year to explore new frontiers before reapplying.

Students are choosing to take a breather; they are thinking. They are not sure what they are going to do. They are going and exploring some of their interests. They are getting experience they can take to the school they finally go to.

It is an idea actively encouraged by colleges. Princeton University has just launched a “bridge year” program that will send 10 percent of its incoming class to do volunteer work abroad, starting in 2009. And the Harvard has spent the last 30 years urging incoming students to take a gap year.

“Many speak of their year away as a ‘life-changing’ experience or a ‘turning point’” says Harvard admissions director Marlin Lewis. “Many come to college with new opinions about their academic plans, their extracurricular interests and the career possibilities they observed in their year away.”

小题1:The reasons why some take a gap year are the following EXCEPT that ________.

A.they hate studying

B.they don’t know what to do

C.they want to get experience

D.they want to know their real interests小题2:A student won’t ________ in a gap year.

A.travel

B.join the army

C.do community service

D.learn a foreign language小题3:After a gap year, one would probably _________.

A.take another year off

B.earn a lot of money

C.be refused by his college

D.have new ideas about their future career小题4:From the passage we know that ________.

A.more and more students will take a gap year

B.fewer and fewer colleges will encourage his students to take a gap year

C.the gap year can only give one some experience about society

D.nobody will change his own interests after the gap year

题型:实验题

机车用直流电机定额,分为连续定额、()定额、断续定额及等效定额4类。

题型:实验题

维生素D缺乏性佝偻病最可靠的早期诊断指标是()

A.日光照射不足及维生素D摄入不足的病史

B.烦躁不安、夜惊、多汗等神经精神症状

C.血钙、磷、碱性磷酸酶水平异常

D.长骨X线检查异常及骨骼畸形

E.血25-(OH)-VD与1,25-(OH)2-VD3水平下降

题型:实验题

在Excel中创建图表,最常用的方法是用______.

A.“数据”菜单项

B.“图表向导”

C.“图表”菜单项

D.“默认图表”按钮

题型:实验题

0.05级饱和标准电池的参考温度范围是()。

A、15~25℃

B、10~40℃

C、10~35℃

D、15~35℃

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