Destructive insects in larger numbers are finding Alaska forests to be a comfortable home and climate change could be the wel-come mat.
Warmer winters kill fewer insects. Lon-ger, warmer summers let insects complete a life cycle and reproduce in one year instead of two. Warm winters also can damage trees and make them less able to stop insect attacks by changing the nature of snow. Instead of light snow formed at extremely cold tempera-tures, warm winters produce wet, heavy snow more likely to break the tops of spruce trees because they are not well adapted to handling big, heavy, wet snow loads.
Since 1980, spruce bark (樹(shù)皮) beetles have killed mature white spruce trees on 4. 4 million acres. For lack of two cold winters on end, the numbers of the beetles there blew up while the resistance (抵抗力) of the trees was down at the same time everywhere. Most of the mature trees have been killed in some whole region of the state.
Spruce bark beetles bore into (蛀穿)trunks and feed on the live cambium layer, a thin part of tissue between bark and wood. Trees re-sist beetles with pitch, made up of hydrocarbons including up to 17 forms of terpene (松稀). The rates of those terpenes are a signal of the health of the tree. When a tree is injured, terpene rates go off in one direction.
Using complex chemical receptors (感受 器), spruce bark beetles discover differences in terpenes. Injured trees offer less resistance.
They smell the tree. If the tree's healthy,they try to avoid it Why? If they start to bore into a healthy tree, it's got a lot of pitch, and the pitch is under high pressure. It's boring in and the pitch is pushing it back out.
(1) What would be the best title for the text?
[ ]
A.The Destruction of Forests in Alaska
B.Warm Winters and Its Bad Effects
C.The Way of Spruce Trees' Living in Alaska
D.Destructive Insects on Rise in Alaska
(2) According to the text, how do warm win-ters reduce the trees' ability to resist in-sect attacks?
[ ]
A.By changing the nature of snow.
B.By offering too much water to trees.
C.By making the weather drier.
D.By increasing the insects' growth speed.
(3) The third paragraph mainly tells________.
[ ]
A.winters are warmer and warmer
B.there are more and more beetles
C.the situation of trees is much worse
D.mature trees are easy to be attacked
(1) 本題要求選擇最佳標(biāo)題。本文主要講述了破壞性的昆蟲(chóng)漸漸地適應(yīng)了阿拉斯加的氣候, 數(shù)量在不斷增加,而且部分昆蟲(chóng)對(duì)樹(shù)木進(jìn)行了大量的破壞,危及當(dāng)?shù)氐纳帧9?/FONT>D正確。(2) 細(xì)節(jié)理解題。根據(jù)文章第二段中“stop in-sect attacks by changing the nature of snow”可知,warm winters通過(guò)改變降雪的性質(zhì)降低了樹(shù)木阻止昆蟲(chóng)侵襲的能力。故A正確。(3) 段落大意題。由文章第三段可知自1980年以來(lái),樹(shù)木的形勢(shì)越來(lái)越嚴(yán)峻,因?yàn)楹芏嗟臉?shù)木已經(jīng)死亡,故C正確。 |
年級(jí) | 高中課程 | 年級(jí) | 初中課程 |
高一 | 高一免費(fèi)課程推薦! | 初一 | 初一免費(fèi)課程推薦! |
高二 | 高二免費(fèi)課程推薦! | 初二 | 初二免費(fèi)課程推薦! |
高三 | 高三免費(fèi)課程推薦! | 初三 | 初三免費(fèi)課程推薦! |
科目:高中英語(yǔ) 來(lái)源:浙江省六校聯(lián)盟2012屆高三第一次聯(lián)考英語(yǔ)試題 題型:050
|
查看答案和解析>>
科目:高中英語(yǔ) 來(lái)源: 題型:閱讀理解
He also started “24 club”, where you would sit in a circle and drink twenty four tall bottles of beer, one after another, until they were gone. I knew there was no future in any of it and that eventually he would self?destruct if he continued using this drug. However, he had been my best friend since grade school, and I didn't have a lot of other close friends. I didn't want to be a loner, but I also didn't want to end up where I thought Jack was going.
I remember finally deciding sadly that it was just too risky to hang out with him any more. And so during my senior year I had to start over making friends. At first I felt awkward, didn't fit in, and felt dumb being alone. But after a few months I made friends with guys who had similar values and also a lot of fun.
My old friend Jack turned into a druggie (癮君子), barely graduated, and eventually drowned in a swimming pool while intoxicated (喝醉的). It was sad, but I was grateful I had the courage to stick with the_right_decision and long?term thinking at a key time in my life.
If you're having trouble making good friends, remember that your friends don't always have to be your age. I once spoke to a guy who seemed to have a grandpa who listened to him and was a great friend. This seemed to fill the friendship blank he had in his life. All in all, just be wise when choosing friends, because much of your future relies on who you hang out with.
1.What does the passage mainly tell us?
A.Making friends with whoever will accept us.
B.Having no friends for a time is better than having the wrong friends.
C.Making as many friends as possible.
D.Not making friends with those who take drug.
2.The reason why the author decided to break up with Jack is that ________.
A.a(chǎn)ny kid who takes drug will drown eventually
B.a(chǎn) kid's future may depend on who he makes friends with
C.a(chǎn)nyone's future relies on who he hangs out with
D.making friends with those who have similar values though you're not accepted
3.What does the underlined part “the right decision” refer to?
①He broke up with the friend who took drug.
②He made new friends with those who had similar values.
③He persuaded Jack to give up taking drug.
④He had trouble in making friends.
A.①② B.③④ C.①③ D.②④
查看答案和解析>>
百度致信 - 練習(xí)冊(cè)列表 - 試題列表
湖北省互聯(lián)網(wǎng)違法和不良信息舉報(bào)平臺(tái) | 網(wǎng)上有害信息舉報(bào)專(zhuān)區(qū) | 電信詐騙舉報(bào)專(zhuān)區(qū) | 涉歷史虛無(wú)主義有害信息舉報(bào)專(zhuān)區(qū) | 涉企侵權(quán)舉報(bào)專(zhuān)區(qū)
違法和不良信息舉報(bào)電話(huà):027-86699610 舉報(bào)郵箱:58377363@163.com