11.They have no brains and no spines (脊椎).You can often see right through them.But they can cause painful,sometimes deadly stings (刺傷).Some can even glow in the dark!Scientists know them as medusas,but most people call them jellyfish.
Jellyfish are not really fish.Jellyfish have stomachs and mouths,but no heads.They have nervous systems for sensing the world around them.They are made almost entirely of water,which is why you can look through them.Most jellyfish live in salt water,apart from a few types that live in fresh water.Jellyfish are found in oceans and seas al over the world.They live in warm,tropical seas and in ice waters near the North and South Poles.
Adult jellyfish are shaped like an open umbrella or a bell.A Jellyfish has tentacles (觸須) at the edges of its body.At the center of a jellyfish's body,where it is widest,is the mouth.The ends of the tentacles have sting cells on them,which jellyfish use to catch their prey (獵物).Some jellyfish have powerful stings that can kill people.
Most jellyfish eat fish,tiny creatures and even other jellyfish.Once a jellyfish stings and catches its prey,it takes the prey to its mouth and swallows it.
Some jellyfish are very small,no longer than a marble (彈子).Others are quite large.The largest jellyfish can grow to about 7feet (about 2meters) across and weight hundreds of pounds!Jellyfish may be blue,orange,pink,yellow,purple,and other colors.
Some jellyfish can glow in the dark by making their own light.The light is made by a chemical reaction inside the jellyfish.Scientists believe jellyfish glow for several reasons.For example,they may glow to attract animals they prey on.
24.What is the second paragraph mainly about?D
A.What jellyfish live on.
B.What jellyfish look like.
C.How jellyfish move.
D.What jellyfish are.
25.What is in the center of a jellyfish's body?B
A.Its brain.
B.Its mouth.
C.Its nervous system.
D.Its stomach.
26.How does a jellyfish catch and eat its prey?C
A.It stings and catches its prey,then sends it into its mouth to chew it.
B.It bites the prey with its mouth,chews it with its teeth and then swallows it.
C.It stings the prey with its tentacles and then swallows it directly.
D.It tears the prey into small pieces and sends it into its mouth to swallow it.
27.What can we learn from the text?A
A.Some jellyfish can make a person die.
B.Most jellyfish live in fresh water.
C.Most jellyfish can be planted in the ocean.
D.Jellyfish only have five colors.
分析 本文是一篇說明文.主要介紹了水母的相關(guān)內(nèi)容.水母不是一種魚,而是一種可以致人死亡的海洋生物.
解答 24.D 主旨大意題.根據(jù)文章第一段They have no brains and no spines (脊椎).You can often see right through them.Jellyfish are not really fish.以及第二段第一句"Jellyfish are not really fish."就可以看出本段主要介紹了"什么是水母".故選D.
25.B 細節(jié)理解題.由第三段第三句"At the center of a jellyfish's body,where it is widest,is the mouth."可知在水母身體的中央是其嘴巴.故選B.
26.C 細節(jié)理解題.由第三段最后一句"The ends of the tentacles have stinging cells on them,which jellyfish use to paralyze and catch their prey."及第四段第二句"Once a jellyfish stings and paralyzes its prey,it takes the prey to its mouth and swallows it."可知水母通過觸須的終端刺傷獵物,然后送進嘴里后直接吞掉,故C項正確.
27.A 推理判斷題.由第一段第三句"But they can cause painful,sometimes deadly stings."可知一些水母甚至能讓人死亡.故選A.
點評 本文是科教類閱讀理解.做這類題材閱讀理解時要求考生對文章通讀一遍,做題時結(jié)合原文和題目有針對性的找出相關(guān)語句進行仔細分析,結(jié)合選項選出正確答案.推理判斷題也是要在抓住關(guān)鍵句子的基礎上合理的分析才能得出正確答案,切忌胡亂猜測,一定要做到有理有據(jù)