（一）PuttingPlantstoWork根据以下材料，回答问题Usingthepowerofthesunisnothingnew.Peopleha

共享题干题 （一）Putting Plants to Work根据以下材料，回答问题 Using the power of the sun is nothing new. People have had solar-powered calculators and buildings with solar panels for decades. But plants are the real experts: They've been using sunlight as an energy source for billions of years. Cells in the green leaves of plants work like tiny factories to convert sunlight, carbon dioxide, and water into sugars and starches, stored energy that the plants can use. This conversion process is called photosynthesis. Unfortunately, unless you're a plant, it's difficult and expensive to convert sunlight into storable energy. That's why scientists are taking a closer look at exactly how plants do it. Some scientists are trying to get plants, or biological cells that act like plants, to work as miniature photosynthetic power stations. For example, Maria Ghirardi of the National Renewable Energy Laboratory in Golden, Colo., is working with green algae. She's trying to trick them into producing hydrogen instead of sugars when they perform photosynthesis. Once the researchers can get the algae working efficiently, the hydrogen that they produce could be used to power fuel cells in cars or to generate electricity. The algae are grown in narrow-necked glass bottles to produce hydrogen in the lab. During photosynthesis, 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. It's the oxygen in the air that prevents algae from making hydrogen most of the time. Working in an air-free environment, however, is difficult. It'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. Unfortunately, removing the sulfate also makes the algae'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 cells' activity and produce larger quantities of hydrogen. The researchers hope that algae will one day be an easy-to-use fuel source. The organisms 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. There's a lot of flexibility in how you can use these organisms."1.[不定向选择题]Who may be able to speed the cells' activity and produce larger quantities of hydrogen?A.Sulfate B.Hydrogen itself. C.Sunlight D.Environment 2.[不定向选择题]According to the fifth paragraph, under what conditions are algae able to use solar energy to make hydrogen ?A.When there is a lot of oxygen in the air. B.When there is no oxygen in the air. C.When photosynthesis is taking place. D.When enough starch is stored.

1.参考答案：A
参考解析：细节题。题干：谁能加速细胞的活动，并产生大量的氢气?文章第六段可以看出，碳酸盐越多，细胞活动越快，产生的氢越多。故A正确。
2.参考答案：B
参考解析：细节题。题干：从第五段可知，在什么样的情况下，海藻能使用太阳能来产生氢气?文章第四段告诉我们“…algae will produce hydrogen in an air flee environment．”，由此可知没有空气的情况肯定就没有氧气了。该段最后一句又说，氧阻止绿藻制造氢。因此本题正确答案为B。3.[不定向选择题]What is NOT true of algae?A.They are easy to grow. B.They can be a very good fuel source. C.They are cheap to eat. D.They can be used in many ways.

这个问题我还想问问老师呢

如以上回答内容为低俗、色情、不良、暴力、侵权、涉及违法等信息，可以点下面链接进行举报！

点此我要举报以上问答信息