1.九年級英語聽力訓練材料
九年級英語聽力：外星人來電
Suppose one day scientists pick up a transmissionthey think isgenerated by aliens.
假如有一天，科學家收到到外星人發(fā)來的信號該怎么辦呢?
Now what? Do we build a landing strip andbreak outthe welcome wagon?
我們有建造飛碟起落跑道來歡迎它們嗎?
Well here's the thing about picking up alienbroadcasts.
關(guān)于接收到外來廣播的事情是這樣的。
The receivers scientists are currently using to listento space noise are designed to find constantsignals,or signals that are pulsing at regular intervals.
科學家接者收目前會聽航天噪音，然后找出不變信號或者找出那些常規(guī)跳動的信號。
But any message carried by these signals wouldprobably be lost because the receivers can't pickup the modulation, or rapid variations, in thebase signal.
但是任何攜帶信息的信號都可能丟失，因為接收者在信號基地不能收集到變調(diào)或快速變化的信號。
The SETI institute, which searches for extra terrestrial life, has compared picking up asignal'smodulation to picking up the sound of a flute when it's masked by the noise of a waterfall.
對外星智能的探索研究院，專門尋找外星生物。它他們對接受到信號的變調(diào)和被瀑布聲掩蓋的笛聲做了比較。
Luckily, scientists would still have enough data to pinpoint where in the sky the transmissioniscoming from.
幸運的是，科學家們有足夠的數(shù)據(jù)來確定信號廣播的位置。
And any slow changes in the broadcast frequency would reveal information aboutthe rotationand movement of the aliens' planets.
廣播頻率的細微變化都會揭露外星人星球的旋轉(zhuǎn)和運動情況。
Okay, but how will we know if they are friendly?
2.九年級英語聽力訓練材料
九年級英語聽力：地球上最成功的物種
For many scientists, a species'success is measuredby sheer numbers.
對很多科學家來說，一個物種的成功完全取決于數(shù)量。
In that case, the most successful species knowntoman is a type of bacterium known as S-A-R-11, orSAR-11 for short.
如果是那樣是話，為人類所知的最成功的物種就是一種簡稱“SAR-11”的細菌。
Scientists estimate that there are two-hundred andforty times a billion billion billion SAR11 cells floatingaround in the oceans.
科學家們估計海洋中的SAR11細胞的數(shù)量超過2 x 10的28次方個。
Now that makes six-billion humans sound like a merehandful.
那讓60億人類聽起來屈指可數(shù)。
SAR11 bacteria are known for their ability to transform one substance into another, which iswhythey are such an important part of the Earth's chemical cycles.
SAR11細菌以其轉(zhuǎn)換物質(zhì)的能力為人所知。而這也使得它們成為地球化學循環(huán)中重要的部分。
Although scientists are stilluncertain about SAR11's specific role, it appears to produce carbondioxide using the oxygen andcarbon from organic matter that's derived from photo synthesis.
盡管科學家不能確定SAR11的具體作用。但它似乎可以使來自于光合作用的氧氣和有機物種的碳發(fā)生作用，產(chǎn)生二氧化碳。
Scientists speculate that SAR11plays a major role in the way the ocean's surface acts as agiant carbon pump that removescarbon dioxide from the atmosphere.
科學家推測SAR11在海洋表面扮演著重要的作用，作為一個巨大的碳泵移除空氣中的二氧化碳。
The catch is that SAR11 is what is known as an uncultured organism, which means thatscientistshaven't been able to cultivate it under laboratory conditions.
但目前SAR11是為培養(yǎng)生物，也就是說科學家不能在實驗室里培養(yǎng)出這種細菌。
3.九年級英語聽力訓練材料
九年級英語聽力：做個樂觀主義者
Research shows that whether a person is an optimistor apessimist is related to their quality of life,including their physical health.
研究表明，不管一個人是樂觀還是悲觀，都他的生活質(zhì)量息息相關(guān)，包括身體健康。
The subjects involved first took personality tests inthe1960's and then thirty years later they completeda follow-up self-assessment of their healthstatus.
這個主題首次在二十世紀六十年代提出并做了人格測試，三十年后他們后續(xù)完成了健康狀況的自我評價。
Researchers found that not only did the optimistsfrom the 1960's report better physicaland mental functioning thirty years later, but thatoptimists also lived longer on average than pessimists.
研究人員發(fā)現(xiàn)60年代的樂觀主義者不僅身心比30年后的人更健康，而且樂觀主義者比悲觀主義者更長壽。
It's hardly clear that there is a causal relationship between optimism and health.
很難理清樂觀與健康之間的因果關(guān)系。
it could be thatthey are related to the same underlying gene complex or set of mechanisms.
也許是因為它們與相同的潛在基因或是一套機制有關(guān)。
Still, it sure istempting to surmise that it's partly a positive attitude that keeps people alive forso long.
不過，可以肯定的是，一定程度上的積極心態(tài)能讓人長壽。
It mayactually be possible that a lot of what my parents have been telling me for years is true.
實際上可能多年來我父母告訴我的許多事情都是真的。
If you think positively, good things may happen to you.
如果你積極地看待這個世界，好的事情就可能發(fā)生在你身上。
