【正文】 hesis, plants normally make sugars or starches. But under certain conditions, a lot of algae are able to use the sunlight energy not to store starch, but to make hydrogen. Ghirardi says. For example, algae will produce hydrogen in an air free environment. It39。s the oxygen in the air that prevents algae from making hydrogen most of the time. 在實(shí)驗(yàn)室里，藻類生長(zhǎng)通過狹窄的頸玻璃瓶生產(chǎn)氫氣的環(huán)境下。在光合作用下，植物通常產(chǎn)生糖類或淀粉。奇若蒂說： ―但在一定條件下，有很多藻類能夠利用日光能源產(chǎn)生氫氣而不是儲(chǔ)存淀粉。 ‖例如，藻類會(huì)在空氣存在環(huán)境下產(chǎn)生氫氣。這是因?yàn)榭諝庵械难鯕?，氧阻止綠藻制造氫。 Working in an air free environment, however, is difficult. It39。s not a practical way to produce cheap energy. But Ghirardi and her colleagues have discovered that by removing a chemical called sulfate from the environment that the algae grow in, they will make hydrogen instead of sugars, even when air is present. 藻類在空氣中雖然可以工作，但是充滿困難。這種方式不能切實(shí)可行的生產(chǎn)廉價(jià)的能源。但是奇若蒂和她的同事們已經(jīng)發(fā)現(xiàn)，即使在目前的空氣條件下，他 們從藻類生長(zhǎng)的環(huán)境中，除去所謂的硫酸化學(xué)品，能夠產(chǎn)生氫來代替糖。 Unfortunately, removing the sulfate also makes the algae39。s cells work very slowly, and not much hydrogen is produced. Still, the researchers see this as a first step in their goal to produce hydrogen efficiently from algae. With more work, they may be able to speed the cells39。 activity and produce larger quantities of hydrogen. 只可惜消除硫酸鹽不僅使藻類細(xì)胞的工作速度減慢，而且大大減少了氫的數(shù)量。盡管如此，研究人員認(rèn)為，對(duì)于實(shí)現(xiàn)有效率的利用藻類產(chǎn)生氫這一目標(biāo)，他們已經(jīng)邁出了第一步。隨著工作量的加大，他們可以加速細(xì)胞的活動(dòng)，從而產(chǎn)生大量的氫氣。 The researchers hope that algae will one day be an easytouse fuel source. The anisms are cheap to get and to feed, Ghirardi says, and they can grow almost anywhere: You can grow them in a reactor, in a pond. You can grow them in the ocean. There39。s a lot of flexibility in how you can use these anisms. 研究人員們希望，總有一天藻類會(huì)成為很容易使用的燃料來源。藻類這種生物極易存活，他們可以在幾乎任何地方成長(zhǎng)。奇若蒂說，： ―你可以將它放在一反應(yīng)堆或是池塘里，也可以在海洋中找到它們，人們可以靈活的使用藻類的用途廣泛。 ‖ 1. What does the writer say about plants concerning solar energy? 關(guān)于植物涉及太陽能，作者說 ? C) Plants have been using solar energy for billions of years. 植物數(shù)十億 年來一直利用太陽能 2. Why do some scientists study how plants convert sunlight carbon dioxide, and water into sugars and starches? 一些科學(xué)家研究植物如何把陽光、二氧化碳、水轉(zhuǎn)化成糖和淀粉的原因backer bag 60 是 ? B) Because they want green plants to bee a new source of energy. 因?yàn)樗麄兿胱尵G色植物變成新的能源 3. According to the fifth paragraph, under what conditions are algae able to use solar energy to make hydrogen? 根據(jù)第五段， ___時(shí)，海藻能用太陽能制造氫氣？ B) When there is no oxygen in the air. 當(dāng)空氣中沒有氧氣 4. Researchers have met with difficulties when trying to make algae produce hydrogen efficiently. Which one of the following is one such difficulty? 研究員們發(fā)現(xiàn)在努力使海藻有效產(chǎn)生氫氣時(shí)存在困難，這樣的困難是 ? D) It is too slow for algae to produce hydrogen when the sulfate is removed. 硫酸鹽被清除后，海藻太慢而不能產(chǎn)生（更多）的氫氣 5. What is NOT true of algae? 于海藻的說法，錯(cuò)誤的是 ?C) They are cheap to eat. 作為食物，它們很便宜 36Listening Device Provides Landslide Early Warning 聽覺儀器提供早期山崩預(yù)警 A device that provides early warning of a landslide by monitoring vibrations in soil is being tested by UK researchers. The device could save thousands of lives each year by warning when an area should be evacuated, the scientists say. Such natural disasters arc mon in countries that experience sudden, heavy rainfall, and can also be triggered by earthquakes and even water erosion. 英國研究者們正在測(cè)試一種儀器，它可以通過監(jiān)測(cè)土壤振動(dòng)提供早期山崩預(yù)告。科學(xué)家們說，這種儀器通過警報(bào)某處有險(xiǎn)情需要撤離，每年可以拯救成千上萬的生命。經(jīng)歷過驟降大耐，地震甚至土壤侵蝕的國家，山崩這樣的自然災(zāi)害是很常見的。 Landslides start when a few particles of soil or rock within a slope start to move, but the early stages can be hard to spot. Following this initial movement, slopes can bee unstable in a matter of hours or minutes, says Nell Dixon at Southborough University1, UK. He says a warning system that monitors this movement might be enough to evacuate a block of flats or clear a road, and save lives. 當(dāng)同一個(gè)山坡上的一些土壤或石塊開始移動(dòng)時(shí)，山崩就開始了，但早期很難發(fā)現(xiàn)。接著 這個(gè)初始運(yùn)動(dòng)， ―山坡在數(shù)分鐘或數(shù)小時(shí)內(nèi)變得不穩(wěn)定， ‖英國拉夫堡大學(xué)尼爾 迪克森說。他說，一個(gè)監(jiān)控這種運(yùn)動(dòng)的警報(bào)系統(tǒng) ―足以疏散一個(gè)，街區(qū)的人或清出一條馬路，拯救生命 ‖。 The most mon way to monitor a slope for signs of an imminent landslide is to watch for changes in its shape. Surveyors can do this by measuring aside directly, or sensors sunk into boreholes or fixed above ground can be used to monitor the shape of a slope. Slopes can. however, change shape without triggering a landslide, so either method is prone to causing false alarms. Now Dixon39。s team has developed a device that listens for the vibrations39。 caused when particles begin moving within a slope. 監(jiān)視迫近的山崩，最常見的辦法就是觀察這座山形狀的變化。研究者們可以直接測(cè)量，也可以在鉆孔中或者地表面上探測(cè)山坡形狀的變化?？墒?，山坡改變形狀也未必就導(dǎo)致山崩。所以任何一種方法都可能導(dǎo)致誤警?，F(xiàn)在，迪克森的團(tuán)隊(duì)已發(fā)明了一種儀器，它在一個(gè)山坡內(nèi)的顆粒開始移動(dòng)時(shí)可以接收到振動(dòng)。 The device takes the form of a steel pipe dropped into a borehole in a slope. The borehole is filled in with gravel around the pipe to help transmit highfrequency vibrations generated by particles within the slope. These vibrations pass up the tube and are picked up by a sensor on the surface. Software analyses the vibration signal to determine whether a landslide may be imminent. 這個(gè)儀器是鋼管形狀，探人山坡上的一個(gè)鉆孔中。鉆孔中儀器的四周填滿沙礫，有助于傳導(dǎo)山坡內(nèi)顆粒產(chǎn)生的高頻振動(dòng)波。振動(dòng)波順著鋼管上傳，被地表傳感器接收。通過軟件分析振動(dòng)信號(hào)，判斷是否馬上要發(fā)生山崩。 The device is currently being tested in a 6metretall artificial clay embankment in Newcastle2, UK. Early results suggest it should provide fewer false positives than existing systems. Once it has been carefully and thoroughly tested, the device could be used to create a plete early warning system for dangerous Slopes. 目前這種儀器正在英國紐卡斯?fàn)栆蛔?6 米高人造石灰大壩中接受測(cè)試。先期結(jié)果顯示它比現(xiàn)有的儀器提供較少的判斷誤差。一旦這種儀器通過了認(rèn)真徹底的檢測(cè)，它將成為 —個(gè)完善的山崩早期預(yù) 警系統(tǒng)。 Locations with a significant risk of landslides could definitely benefit from a machine like this, says Adam Poulter,