[E] The size and weight of fuel cells have always been problems. New fuel-cell technology promises to solve those issues.
[F] Fuel cells can use various sources of hydrogen, including a simple tank of compressed gas. But methanol, a liquid usually produced from natural gas, is a much more efficient way to store hydrogen. This is why the first wave of fuel cells in cars will likely use an indirect methanol fuel cell, in which the methanol passes through a mechanism called a “reformer”, which extracts the hydrogen.
[G] A new, lightweight fuel cell that runs on methanol may one day power your electric car. Sooner still, the new cell may fuel smaller devices such as your lap-top computer or mobile phone.
Order:
G
41.
42.
43.
44.
45.
F
III. English-Chinese Translation
1) It is the business of the scientist to accumulate knowledge about the universe and all that is in it, and to find, if he is able, common factors which underlie and account for the facts that he knows. He chooses, when he can, the method of the “controlled experiment”. If he wants to find out the effect of light on growing plants, he takes many plants, as alike as possible. Some he stands in the sun, some in the shade, some in the dark, all the time keeping all other conditions (temperature, moisture, nourishment) the same. In this way, by keeping other conditions constant, and by varying the light only, the effect of light on the plants can be clearly seen. 2) This method of using “controls” can be applied to a variety of situations, and can be used to find the answers to questions as widely different as “Must moisture be present if iron is to rust?” and “Which variety of beans gives the greatest yield in one season? ”
In the course of his inquiries the scientist may find what he thinks is one common explanation for an increasing number of facts. The explanation, if it seems consistently to fit the various facts, is called a hypothesis. If a hypothesis continues to stand the test of numerous experiments and remains unshaken, it becomes a law.
3) The scientist is always most gratified to find that an underlying “explanation” of many phenomena suggests in its turn the possibility of proving its own accuracy or falsity by a suitably arranged critical experiment. He is also gratified when his “explanation”, if true, points to a new series of experiments designed to answer a new set of questions. For the curiosity of the scientist is never satisfied.
The evidence as to the vastness of the universe and the complexity of its arrangements continues to grow at an amazing rate. The gap between what we know and all that can be known seems not to diminish, but rather to increase with every new discovery. Fresh unexplored regions are forever opening out.
4) The rapidity of the increase of scientific knowledge, in the nineteenth and twentieth centuries, is apt to give students and teachers the impression that no sooner is a problem stated than the answer is forthcoming. A more detailed study of the history of science corrects the impression that fundamental discoveries are made with dramatic suddenness. Even in our present age no less than fifty years separate the discovery of radioactivity from the explosion of the first atomic bomb. Much of the fundamental information which now enables us to control the onset and duration of disease was known a century ago. |
