参考译文
世界上最好的两三天以上的天气预报具有很强的猜测性，如果超过六七天，天气预报就没有了任何价值。
原因是蝴蝶效应。对于小片的恶劣天气——对一个全球性的气象预报员来说，“小”可以意味着雷暴雨和暴风雪——任何预测的质量会很快下降。错误和不可靠性上升，接踵而来的是一系列湍流的微状，从小尘暴和暴风发展到只有卫星上可以看到的席卷整块大陆的旋涡。
现代气象模型以一个坐标图来显示，图中每个点大约是间隔60英里。
既使是这样，有些开始时的资料也不得不依靠推测，因为地面工作站和卫星不可能看到地球上的每一个地方。假设地球上可以布满传感器，每个相隔1英尺，并按1英尺的间隔从地面一直排列到大气层的顶端。再假定每个传感器都极端准确地读出了温度、气压、湿度和气象学家需要的任何其他数据。在正午时分，一个功能巨大的计算机搜集了所有的资料，并算出在每一个点上 12∶01、12∶02、12∶03时可能出现的情况。
计算机无法推断出1个月以后的某一天，
新泽西州的普林斯顿究竟是晴天还是雨天。正午时分，传感器之间的距离会掩盖计算机无法知道的波动、任何偏离平均值的变化。到12∶01时，那些波动就已经会在1英尺远的地方造成偏差。很快这种偏差会增加到10 英尺的范围，如此等等，一直到全球的范围。
Comprehension理解
Give short answers to these questions in your own words as far as possible．Use one complete sentence for each answer.
1What does the author mean by‘small pieces of weather’?
2How do modern weather models work ?
3What do you think‘the butterfly effect’means in this passage?
Vocabulary词汇
Refer to the text to see how the following words have been used, then write sentences of your own using these words: speculative (1.1); global (1.3); deteriorates (1.4); rapidly (1.4); multiply (1.4); turbulent (1.5); suppose (1.10); accurate (1.10); precisely (1.11); data (1.12); fluctuations (1.14); average (1.15); errors (1.16).
The paragraph段落
AWhich one of these statements do you think the author would agree with?
1Accurate readings by computers enable us to predict the weather.
2It will never be possible to predict the weather accurately.
3The only way to predict the weather accurately is to have sensors one foot apart, rising at one-foot intervals all the way to the top of the atmosphere.
Key structures关键句型
ANote how these two sentences have been connected:
Errors and uncertainties multiply．They cascade upward through a chain of turbulent features.
Errors and uncertainties multiply, cascading upward through a chain of turbulent features．(11.4-5)
Join these sentences in the same way:
1There's a fault in the earth's crust．It runs along the west coast of the USA.
2The hurricane hit Florida．It swept away everything in its path.
3I noticed the lights were on．I assumed they were at home.
4He emerged from the airport．The president waved to the reporters.
BWe can introduce conditional sentences with conjunctions other than if, for example:
Suppose the earth could be covered with sensors spaced one foot apart．(11.8-9)
Complete these sentences in any way you like:
1You can go home early, providing (that) ______.
2We can offer you a job on condition (that) ______.
3You can come in any time you like tomorrow morning so long as ______.
4I won't phone you unless ______.
5He'll definitely win even if ________.
CStudy these two sentences:
We will probably have some rain by noon.
By 12.01those fluctuations will already have created small errors one foot away．(11.15-16)
Explain the differences in meaning between these pairs of sentences:
1He won't receive this fax tomorrow morning.
He will have received this fax by tomorrow morning.
2He won't leave Beijing until this message arrives.
By the time this message arrives, he will have left Beijing.
3They will complete the new motorway by next June.
They won't have completed the new motorway until next June.
Special difficulties难点
AExplain the meaning of since in these sentences:
1Some starting data has to be guessed, since ground stations and satellites cannot see everywhere.
2John feels much happier since he changed his job．
3Susan left in July and we haven't seen her since.
4It hasn't stopped raining since eight o'clock this morning.
5Since you're so clever, see if you can solve the problem!
BThe computer will be unable to predict whether Princeton, New Jersey, will have sun or rain on a day one month away．(11.13-14)
Supply if or whether; note the sentences where we can use both if and whether.
1_____ he has signed the contract (or not) doesn't matter.
2The question is ______ he has signed the contract.
3I want to know _______ he has signed the contract.
4I'm concerned about ______ he has signed the contract.
5Do you know ______ she's arriving by bus or by car?
Multiple choice questions多项选择题
Choose the correct answers to the following questions.
Comprehension理解
1The reason it's hard to forecast the weather is that ______.
a．conditions rapidly deteriorate
b．there is always turbulence
c．only satellites have a panoramic view of conditions
d．the effect of tiny changes cannot be detected or calculated
2Even with grid points which are sixty miles apart, forecasters_____.
a．have to depend on satellites for information
b．have to make assumptions about some of the data
c．work on modern weather models
d．prevent errors from multiplying
3Which of these statements is true?
a．The only way to solve the problem is to have sensors spaced at one-foot intervals.
b．The only way to solve the problem is to have infinitely powerful computers.
c．The only way to solve the problem is to have perfectly accurate readings.
d．At present, there is no way of making absolutely accurate predictions.
4Tiny variations in temperature, pressure and humidity _____.
a．will be picked up by sensors at one-minute intervals
b．are used to predict the weather one month ahead
c．can lead to completely unexpected weather conditions
d．produce expected results
Structure句型
5Generally speaking, any prediction ______ rapidly．(1.2)
a．is deteriorating
b．has deteriorated
c．will deteriorate
d．had deteriorated
6Only satellites _______ see continent-size features．(11.5-6)
a．are able to
b．could
c．are possible
d．are capable
7_____ the earth could be covered with sensors．(11.9-10)
a．Providing that
b．On condition that
c．Say
d．Allowing that
8The computer will be incapable ______ whether Princeton will have sun or rain one month away.(11.13)
a．predict
b．to predict
c．of predicting
d．predicting
Vocabulary词汇
9The world's best weather forecasts are based on _______．(1.1)
a．certain knowledge
b．guess work
c．scientific facts
d．accurate calculation
10The modern weather models work with a _____ of points.(1.7)
a．scale
b．balance
c．line
d．network
11‘Humidity’ refers to ______．(1.11)
a．light
b．water vapour
c．pressure
d．heat
12An infinitely powerful computer takes in all the data and _____ what will happen．(11.11-12)
a．predicts
b．foretells
c．estimates
d．works out |
|
