(2013·新课标Ⅰ，32)There's no way of knowing why one man makes an important discovery________another man，also intelligent，fails.
A．since B．if C．as D．while
高三英语单项填空中等难度题
(2013·新课标Ⅰ，32)There's no way of knowing why one man makes an important discovery________another man，also intelligent，fails.
A．since B．if C．as D．while
高三英语单项填空中等难度题查看答案及解析
(2013·高考新课标全国卷Ⅰ)There’s no way of knowing why one man makes an important discovery________another man，also intelligent，fails.
A．since B．if
C．as D．while
高三英语单项填空中等难度题查看答案及解析
There’s no way of knowing why one man makes an important discovery ________ another man, also intelligent, fails.
A．since B．if C．as D．while
高三英语单项填空困难题查看答案及解析
There’s no way of knowing why one man makes an important discovery __________ another man, also intelligent, fails.
A.while B.when C.where D.why
高三英语单项填空中等难度题查看答案及解析
How does an ecosystem(生态系统)work？What makes the populations of different species the way they are？Why are there so many flies and so few wolves？To find an answer，scientists have built mathematical models of food webs，noting who eats whom and how much each one eats.
With such models，scientists have found out some key principles operating in food webs. Most food webs，for instance，consist of many weak links rather than a few strong ones. When a predator(掠食动物)always eats huge numbers of a single prey(猎物)，the two species are strongly linked；when a predator lives on various species，they are weakly linked. Food webs may be dominated by many weak links because that arrangement is more stable over the long term. If a predator can eat several species，it can survive the extinction(灭绝)of one of them. And if a predator can move on to another species that is easier to find when a prey species becomes rare，the switch allows the original prey to recover. The weak links may thus keep species from driving one another to extinction.
Mathematical models have also revealed that food webs may be unstable，where small changes of top predators can lead to big effects throughout entire ecosystems. In the 1960s，scientists proposed that predators at the top of a food web had a surprising amount of control over the size of populations of other species---including species they did not directly attack.
And unplanned human activities have proved the idea of top-down control by top predators to be true. In the ocean，we fished for top predators such as cod on an industrial scale，while on land，we killed off large predators such as wolves. These actions have greatly affected the ecological balance.
Scientists have built an early-warning system based on mathematical models. Ideally，the system would tell us when to adapt human activities that are pushing an ecosystem toward a breakdown or would even allow us to pull an ecosystem back from the borderline. Prevention is key，which scientists says because once ecosystems pass their tipping point(临界点)，it is remarkably difficult for them to return.
1.What have scientists discovered with the help of mathematical models of food webs？
A.The living habits of species in food webs.
B.The rules governing food webs of the ecosystems.
C.The approaches to studying the species in the ecosystems.
D.The differences between weak and strong links in food webs.
2.A strong link is found between two species when a predator______
A.has a wide food choice B.can easily find new prey
C.sticks to one prey species D.can quickly move to another place
3.What conclusion can be drawn from the examples in Paragraph 4？
A.Uncontrolled human activities greatly upset ecosystems.
B.Rapid economic development threatens animal habitats.
C.Species of commercial value dominate other species.
D.Industrial activities help keep food webs stable.
4.How does an early-warning system help us maintain the ecological balance？
A.By getting illegal practices under control.
B.By stopping us from killing large predators.
C.By bringing the broken-down ecosystems back to normal.
D.By signaling the urgent need for taking preventive action.
高三英语阅读理解困难题查看答案及解析
One random act of kindness can make someone’s day, but a man in Florida knows a good ______ isn’t a one-time thing.
After spending three months in and out of the hospital with numerous health issues, Donald Austin had his ______ partially cut off. He was relieved to finally be able to go home after just four days recovering from the ______. When he reached his porch, though, the ______ disappeared.
Donald thought he’d be able to ______ up the steps to the front door on crutches (拐杖), but he found he was too weak to keep his ______. He had to sit in the wheelchair, but the wheelchair was too heavy for his wife, Jennifer Austin, to lift up the steps, even when his mom pitched in. Donald ended up on the ground，the family feeling totally ______.
Just then, a car caught the family’s eye. It had driven past ______ was slowly circling back. The stranger, Steven Smith,______ and asked if he could help.______, the family watched Smith lift Donald inside and lay him ______ on a couch.
But the good man knew there was ______ to do.
Smith ______ this wasn’t the only time Donald would need to climb those ______. So the next day, Smith came back and asked if he could build a ramp (坡道) in front of the house. With his dad and a couple more ______, Smith set up a ramp ______ the steps to make the house ______ to the wheelchair. The act of kindness brought the family to ______.
“This stranger has saved the day for us ______ within 24 hours. He also ______ our spirits that had become increasingly dimmed over the difficult months.” Jennifer wrote on Facebook.
1.A. deed B. manner C. deal D. performance
2.A. leg B. arm C. back D. face
3.A. injury B. depression C. operation D. shock
4.A. regret B. headache C. belief D. joy
5.A. try it B. make it C. put it D. take it
6.A. breath B. balance C. distance D. promise
7.A. at a loss B. in the dark C. for nothing D. out of mind
8.A. though B. while C. but D. when
9.A. broke up B. cut in C. pulled up D. called on
10.A. Horrified B. Embarrassed C. Refreshed D. Relieved
11.A. blindly B. painfully C. carelessly D. safely
12.A. less B. more C. something D. nothing
13.A. figured B. pointed C. commented D. suspected
14.A. roads B. ladders C. rails D. steps
15.A. passers-by B. useful equipment C. honored guests D. helping hands
16.A. around B. over C. under D. into
17.A. accessible B. avoidable C. available D. valuable
18.A. life B. justice C. tears D. normal
19.A. forever B. twice C. once in a while D. at all times
20.A. brightened B. took up C. brought up D. worsened
高三英语完形填空中等难度题查看答案及解析
One businessman was in debt and couldn’t figure out a way out of it when an old man appeared before him.
“Is something bothering you?” he said. After listening to the ___businessman, the old man said: “ I think I can help you.” He wrote him a ___, saying: “Take this money. We will meet here ___in one year, and you will be able to ___it to me at that time.” Then, he turned around and disappeared just as____as he appeared.
The businessman saw the check in his hands for an amount of 500 thousand dollars, ___by John Rockefeller, one of the ___people in the world at that time! But instead of using the money, he put the check into his safe. The thought about its ___gave him strength to find a solution to save his business.
___the return of his courage, he concluded profitable deals. Months ___and he got out of ___and started to earn money again. Exactly one year ___, he returned to the park with the same check. At the ___time the old man appeared again. But ___the businessman wanted to return the check and share his story of ____, a nurse ran up and grabbed the old man.
“I’m so glad, I caught him!” She exclaimed. “I hope he wasn’t ____ you. He always runs away from the house and ___he is John Rockefeller.”
The businessman was puzzled, and suddenly he understood that it’s not the money, ___or imaginary, that turned his life up. It was his new ___and belief that gave him strength to ____ everything that he had now.
1.A. mad B. discouraged C. interesting D. brave
2.A. check B. hand C. lift D. look
3.A. possibly B. exactly C. especially D. generally
4.A. give B. pay C. thank D. return
5.A. suddenly B. strangely C. happily D. firmly
6.A. made B. given C. signed D. paid
7.A. kindest B. richest C. best D. poorest
8.A. number B. value C. usage D. existence
9.A. For B. As C. Despite D. With
10.A. came B. ended C. passed D. went
11.A. danger B. sadness C. trouble D. debt
12.A. ago B. later C. away D. before
13.A. same B. agreed C. counted D. regulated
14.A. when B. before C. after D. if
15.A. happiness B. failure C. success D. sorrow
16.A. scolding B. criticizing C. frightening D. bothering
17.A. tells B. thinks C. praises D. imagines
18.A. false B. real C. wrong D. true
19.A. gains B. bravery C. plan D. confidence
20.A. do B. face C. achieve D. like
高三英语完形填空简单题查看答案及解析
There’s another way to survive this competition -- a way no one ever seems to tell you about, _____ you have to learn for yourself.
| A．one | B．it | C．that | D．another |
高三英语单项填空中等难度题查看答案及解析
There’s no one reason why women return to school. Going back to school provides private and public benefits. College graduates, generally enjoy higher salaries,1.(employ) more consistently, and work in nicer conditions. College-educated people vote more, give more to charity, and rely2.(little) on government support.
Making the switch from3.(support) to supporting oneself can be a challenge,4.often a necessary one. “Financial5.(dependent) for women is key,” says Nancy Schlossberg, a professor at University of Maryland. “I think6.important for women to make some direct achievement, because chances are that women will live alone in later life, either divorced7.never married.”
To Schlossberg, education is critical in the long run. She says, “You are going to do much better than before8.you have a good education; you are going to be happier than before on condition that you have9.education that enables you to do what you have to do in life. The question is10.you are ready at this time to go for it.
高三英语短文填空中等难度题查看答案及解析
The world makes _____ for the man who knows where he is going.
A. method B. approach
C. way D. means
高三英语单项填空简单题查看答案及解析