问题 选择题

下列关于基因的叙述,正确的是[ ]

A.基因突变一定会改变生物的性状

B.基因频率改变一定会导致新物种产生

C.染色体上某个基因的丢失属于基因突变

D.不同基因转录形成的mRNA上相同的密码子可编码相同的氨基酸

答案

答案:D

阅读理解与欣赏

阅读下面的文言文,完成问题。

  林尽水源,便得一山。山有小口,仿佛若有光。便舍船,从口入。初极狭,才通人。复行数十步,豁然开朗。土地平旷,屋舍俨然,有良田美池桑竹之属。阡陌交通,鸡犬相闻。其中往来种作,男女衣着,悉如外人。黄发垂髫,并怡然自乐。

  见渔人,乃大惊,问所从来。具答之。便要)还家,设酒杀鸡作食。村中闻有此人,咸来问讯。自云先世避秦时乱,率妻子邑人来此绝境,不复出焉,遂与外人间隔。问今是何世,乃不知有汉,无论魏晋。此人一一为具言所闻,皆叹惋。余人各复延至其家,皆出酒食。停数日,辞去。此中人语云:“不足为外人道也。”

  既出,得其船,便扶向路,处处志之。及郡下,诣太守,说如此。太守即遣人随其往,寻向所志,遂迷,不复得路。(节选自陶渊明《桃花源记》)

1.解释下列加粗的词。(任选择两个作答,多选不给分)

(1)屋舍俨然 俨然:_____________

(2)阡陌交通 交通:_____________

(3)便还家  要:_____________

(4)不知有汉 乃:_____________

2.把下面文言句子翻译成现代汉语。

此中人语云:“不足为外人道也。”

________________________________________________

3.选段中与陆游诗句“山重水复疑无路,柳暗花明又一村”意境相似的一个成语是,源于本文且借指不受外界影响的地方或幻想中的美好世界的一个成语是________。

4.从选段中可以看出陶渊明所向往的是怎样的一种理想社会?

________________________________________________

5.渔人把桃花源中的秘密告诉了外人,对此你有何看法?

________________________________________________

阅读理解

When we look at the sky and see a bright light moving quickly across it or coming towards the earth, we talk about seeing a “shooting star” or a “falling star”. These moving lights are not, in fact, stars at all. They are small pieces of matter from outer space, which burn up as they enter the Earth’s atmosphere. The correct name of them is meteoroids. Any pieces that make it to the Earth’s surface without completely burning up are known as meteorites. A meteor is actually the name given to the light we see when a meteoroid is burning up.

When a meteorite hits the Earth at speeds between 11 and 72 kilometers a second, it can do amazing damage. A very large meteorite could knock the earth out of its orbit. If this happened, all life on Earth would probably become extinct(灭绝). The path we follow around the Sun would change and as a result the Earth would become either much hotter or much colder. This change in temperature would affect sea levels and the amount of water in rivers. There would either be huge floods, which would cover most of the land with water, or the oceans would dry up and there would be a drought, which means a long period of time without rain. Either way, nothing could survive. If a large meteorite landed in the sea it would almost certainly cause tsunamis, which would race towards the land, destroying everything in their paths.

Although it is unlikely the Earth will be struck by a meteorite large enough to do that kind of damage, there is evidence of fairly large meteorites hitting the Earth in the past. In 1908 a large area of forest in Tunguska, Siberia was destroyed by a meteorite that came apart just before it hit the ground. The moon, however, has about three billion craters陨石坑caused by meteorites impacting影响 its surface. The reason more meteorites have reached the surface of the moon than the surface of the Earth is that the moon does not have enough atmosphere for the meteorites to burn up in. some of the meteorites that have reached the Earth’s surface have done considerable damage. Some scientists believe it was a change of climate caused by meteorites hitting the Earth that resulted in the extinction of the dinosaurs and other large prehistoric animals.

Scientists are especially interested in meteorites because they contain information about the solar system. It is widely believed by scientists that most meteorites are produced by collisions(碰撞) between asteroids (small planets). These collisions probably happened many billions of years ago. This means the physical and chemical structure of a meteorite can give scientists information about the early days of the universe.

小题1:The story is about ___.     

A.floods caused by meteors

B.matter from outer space

C.life on Earth millions of years ago

D.meteorites that have damaged the moon小题2:The Earth has ___.                    

A.three billion craters

B.fewer craters than the moon

C.more craters than the moon

D.a thinner atmosphere than the moon小题3:Some scientists believe the dinosaurs became extinct because ___.     

A.they were hit by meteors

B.meteorites landed on their nests

C.meteorites landed and changed the climate

D.they could no longer breathe the atmosphere小题4:Meteors are ___.                                         

A.small planets

B.the same as asteroids

C.from broken parts of asteroids

D.the light we see when meteoroids hit our atmosphere