(10分)最近,生物学家发现,由于全球气候变暖,原来生活在中纬度的北美洲灰熊的活

题型:实验题

问题:

(10分)最近,生物学家发现,由于全球气候变暖,原来生活在中纬度的北美洲灰熊的活动范围逐渐向北延伸,开始进入北极圈—北极熊的传统领地。这样一来,北极熊的生存将受到威胁,因为灰熊有可能在北极熊生产的洞穴冬眠,并捕杀北极熊幼仔。(原创题)

(1)根据资料分析,在北极圈灰熊是属于             物种。

(2)灰熊和北极熊在生物分类上同属于       动物,它们的共同特点是体表被毛,         

      

(3)北极熊的体色纯白,与北极圈的环境融为一体,这种体色称为             ,这种体色的形成用达尔文的观点来解释是由于              的结果,对于体色这种性状起决定作用的是_______  ___。

(4)灰熊和北极熊都有冬眠现象,这是生物对环境的          ,从行为的获得途径上来

看,冬眠现象属于              行为。

(5)2009年12月在丹麦首都哥本哈根召开世界气候大会,其主要目标是旨在解决全球气候变暖,减少温室气体的排放,下列气体属于温室气体的是(  )                                      

A.氧气

B.二氧化碳

C.二氧化硫

D.氮气

考点:观察实验:饲养和观察蚯蚓动物的生活环境和生活习性动物的形态结构和功能
题型:实验题

肾病综合征浮肿的机理主要是

A.水钠潴留
B.血容量增多
C.血浆胶体渗透压下降
D.醛固酮增多
E.抗利尿激素分泌下降

题型:实验题

经过18个月的精心酝酿和290多万首都市民投票参与,2011年11月1日,“北京精神”表述语“爱国、创新、包容、厚德”正式向社会发布.为了更好地宣传“北京精神”,小明同学参加了由街道组织的百姓宣讲小分队,利用周末时间到周边社区发放宣传材料.第一周发放宣传材料300份,第三周发放宣传材料363份.求发放宣传材料份数的周平均增长率.

题型:实验题

把下面歇后语补充完整。  

(1)下雨出太阳——_________________

(2)八十岁老汉吹唢呐——_________________  

(3)小葱拌豆腐——_________________

(4)看戏淌眼泪——_________________

(5)笔杆子吞进肚——_________________

题型:实验题


It is impossible to find out exactly how many volunteers are at work today in the United States. Thirty-seven million or so are known to belong to (67) like the Pink Ladies, Travelers’ Aid, or Big Brothers’, but those who work (68) or in small informal groups cannot be (69) . The total number of men and women who give their time to help others appears to be between fifty and sixty-eight million.
They do almost anything: they sew, clean, (70) , paint, cook, repair things, (71) books for the blind, (72) sick children in hospitals, or (73) senior citizens who do not want to go out alone. They give their blood; they work in libraries and schools; they (74) documents for new citizens with a language problem or (75) money to support local symphony orchestras; they answer the telephone calls of the (76) who are thinking of killing themselves, and who need a friendly (77) .
Volunteers start community projects too small to attract the attention of organized agencies, or work at jobs (78) no funds are available. A(n) (79) of city folk will turn an empty (80) into a playground for the children of their neighborhood; others decide to repair and paint a few dilapidated houses in their street. (81) Women cook and (82) two hot meals a day to elderly people (83) alone, and too sick or too tired to prepare their own food. (84) group calls lonely old people once a day to chat a little and (85) if they are all right. Some college students teach English, mathematics, or drawing to the inmates of a local jail. Anywhere one looks, the (86) of volunteers is hard at work--not only in the United States, but in many other countries where "volunteerism" is spreading.

A.sought

B.documented

C.searched

D.counted

题型:实验题

某同学利用透明直尺和光电计时器来验证机械能守恒定律,实验的简易示意图如下,当有不透光物体从光电门间通过时,光电计时器就可以显示物体的挡光时间.将挡光效果好、宽度为d=3.8×10-3m的黑色磁带贴在透明直尺上,从一定高度由静止释放,并使其竖直通过光电门.

某同学测得各段黑色磁带通过光电门的时间△ti与图中所示的高度差△hi,并将部分数据进行了处理,结果如下表所示.(取g=9.8m/s2,注:表格中M为直尺质量)

(1)请将表格中带“▲”的空格,数据填写完整(小数点后取2位).

△ti

(10-3s)

vi=
d
t1

(m•s-1

△Eki=
1
2
Mvi2-
1
2
Mv12
△hi

(m)

Mg△hi
11.213.14
21.153.300.52M0.060.59M
31.003.802.29M0.242.35M
40.954.003.07M0.323.14M
50.90____________0.41______
(2)从表格中数据可知,直尺上磁带通过光电门的瞬时速度是利用vi=
d
ti
求出的,请你简要分析该同学这样做的理由是:______.

(3)通过实验得出的结论是:______.

(4)根据该实验请你判断下列△Ek-△h图象中正确的是______

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