题目内容
_____ the high price, demands for these cars are very high.
A.Because of B.In spite of C.In case of D.Thanks to
B
Every country had its heroes. The heroes are the people that nation and especially the young peo??ple 21_____ . If you get a list of the 22 _____of a nation, it will tell you the potential (潜力)of the nation.
If today in America ’ you ask the high school students to list their heroes their 23____ would prob??ably divide into three groups. rHie first group of heroes would be the rock stars—the people 24 _____with rock music. There is no doubt that such people do have talent (天才)but one 25_____ if one should hold up rock stars as model. The rock stars too often are mixed with drugs and their personal life isnot all that — 26 ____ . The rock stars are rich and wear the latest fashion styles (时装).However oneshould 27 _____more in a hero than such things as 28______ and fine clothes.
A second type of heroes for the American youth are sports stars. Again you have a person who has a great talent in one area_ 29 _____. However, too often the personal life of the sports star is a bit 30_____. Too frequently drugs and drinking are a part of 31_____ of the sports stars.
A third group of heroes are TV or movie stars. These people may have lots of 32___ ,tal??ent and are quite handsome. However ’ the personal life of too many actors is quite sad and should not be held up as a 33____ for young people.
Today,the rock stars,the sportsmen and the actors 34____ have become the models of the youth in America. Really,do you hear a young person say that his 35____ is a doctor, a teacher or a scientist? These people are not 36____ and do not wear fashionable clothes. However, they are 37____ people who work hard to make the world a better place for everyone.
What is really sad is that the young try to 38____ their heroes. They like to wear the same clothes as theirs, if the heroes of today for the American youth are 39 ____only to rock stars, sportsmen and actors, the future does not look too 40_____ .
A. | dislike | B. | admire | C. hate | D. | satisfy | |
A. | doctors | B. | soldiers | C. teachers | D. | heroes | |
A. | choice | B. | conclusion | C. answer | D. | questions | |
A. | interested | P. | connected | C. excited | D. | pleased | |
A. | wants | B. | hopes | C. wonders | D. | expects | |
A. | bad | B. | simple | C. silent | D. | good | |
A. | gather | B. | spend | C. put | D. | be after | |
A. | paper | B. | money | C. food | D. | book | |
A. | sports | B. | music | C. movie | D. | teaching | |
A. | regular | B. | disorder | C. happy | D. | hard |
For years, the automobile industry has been testing vehicles that use hydrogen as fuel. Now, people across the United States have had a chance to see and even drive cars that get power from hydrogen fuel cells (燃料电池).
But the hydrogen fuel cell is not a new idea. The fuel cell was first invented by Sir William Grove of Britain in 1839. Since then, many different designs, have been invented. There is one place where fuel cells are a proven technology: in space. The American space agency used fuel cells in its Apollo spaceships in the twentieth century.
The most useful fuel cell for transportation purposes is the Polymer Electrolyte Membrane, or P.E.M. fuel cell. It is simple and can operate at temperatures of sixty to eighty degrees Celsius. That is much lower than other fuel cell designs. A P.E.M. fuel cell has two sides divided by a thin membrane (膜). Hydrogen gas is forced through one side where it comes in contact with a reactive material containing the metal platinum(铂). The membrane separates the electrons(电子) from the protons(质子) in the hydrogen atoms. The protons pass through it to the other side of the fuel cell. But the electrons are captured to do work; like powering a motor. Oxygen from the air is forced into the other side of the fuel cell. There, the gas meets the protons that have passed through the membrane. They combine to form water and heat. A single fuel cell does not produce a lot of electricity. But when many fuel cells are combined, they can produce enough electricity to power a vehicle. The product of the chemical reaction that powers fuel cells is water. This makes fuel cells a very clean technology.
Hydrogen fuel cell cars have been slow to develop because of many technical problems that have to be solved. For example, it is unclear how long the membranes in P.E.M. fuel cells will last. Also, fuel cells need water for their chemical reactions. They must be designed to start easily at low temperatures and in dry climates. And smaller, less costly fuel cells must be designed before they can truly take the place of gasoline engines. Now more models of fuel cell vehicles are being tested than ever before. The threat of climate change and the high cost of oil have increased interest in these vehicles that do not cause pollution.
Title |
More Models of Hydrogen Cars Being Tested |
The progress of hydrogen fuel cell |
·(1) ________ by Sir William Grove in 1839. ·Designed (2) ________ ever since. ·Used in Apollo spaceships in the twentieth century. |
Operating principle of P.E.M. |
·It has two sides divided by a thin membrane. ·Hydrogen gas from one side (3) ________ the active metal platinum. ·The electrons are (4) ________ from the protons in the hydrogen atoms. ·The protons pass through the fuel cell to the other side. ·Oxygen from the air is (5) ________ into the other side of the fuel cell. ·The gas meets the protons,and then water and heat are(6) ________ |
Reasons for slow (7) ________of hydrogen fuel cell cars |
·There are many technical problems (8) ________ ·The durability of the membranes in P.E.M. fuel cells is not clear. ·They have to start easily at (9)________ temperatures and in dry climates. ·They must be smaller and less costly before (10) ________ gasoline engines. |