Most of the flowers in nature are red, o

题型:阅读理解

问题:

Most of the flowers in nature are red, orange and yellow. If we have seen a black flower, it’s a chance in million. People have made a census ( 普查 ) to colors of more than four thousand kinds of flowers and discovered that only eight of them are black. As we know, sunlight is formed by seven different colored lights. The wave length of each light is different, so the quantity of heat in each light is also different. Flowers, especially their petals ( 花瓣 ) , are easy to be harmed by high temperature. Black flowers can take in all the light waves which cause the flowers to dry up in a high temperature. So black flowers can rarely survive sunlight. But red flowers, orange flowers and yellow flowers can protect themselves from sunlight by reflecting the red light, orange light and yellow light, each of which has a large quantity of heat.

小题1:It is _________ to see a black flower.

A.impossible

B.seldom

C.common

D.no chance小题2:The passage tells us that ________________.

A.black flowers are so weak that it is difficult for them to grow up.

B.there is only eight black flowers in nature.

C.sunlight is formed by seven different colored lights, so the wave length of each light is different.

D.black flowers can take in the light of all the wave lengths which make them dry up because of high temperature.小题3:Which of the following ideas is NOT true?

A.People have found that only a few kinds of flowers are black.

B.Flowers are easy to be harmed by very high temperature.

C.Red, orange and yellow flowers can also absorb the light of all wave lengths.

D.The black flowers cannot protect themselves from sunlight.

考点:科教类阅读
题型:阅读理解

A glue that holds the whole Internet together is the network layer protocol, (1) .Unlike most older network layer protocols, it was designed from the beginning with internetworking in mind. Its job is to provide a (2) way to transport data grams from source to destination, without regard to whether these machines are on the same network or whether there are other networks in between them.

Communication in the Internet works as follows. The (3) layer takes data streams and breaks them up into data grams. Each datagram is transmitted through the Internet, possibly being fragmented into smaller units as it goes. When all the pieces finally get to the destination machine, they are reassembled by the (4) layer into the original datagram. This datagram is then handed to the transport layer, which inserts it into the receiving process’ input stream.

An IP datagram consists of a header part and a text part. The header has a (5) part and a variable length optional part.

4()

A.data link

B.transport

C.network

D.application

题型:阅读理解

属于共济失调中运动性失调的是()

A.脊髓性失调

B.前庭性失调

C.延脑性失调

D.小脑性失调

E.大脑性失调

题型:阅读理解
如果a是
1
5
的倒数,那么a的
3
5
是______.
题型:阅读理解

生物多样性丧失的影响因素有哪些?

题型:阅读理解

在火灾探测器中,极具发展前途的火灾探测器是( )火灾探测器。

A.感烟
B.感光
C.复合式
D.气体

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