自并激励发电机对继电保护有什么影响？应采取什么措施？

Gasoline (汽油) prices are getting higher and higher. The prices make it hard for drivers to afford the fuel.
One group held a special event to display（展示）new kinds of cars .
The new cars are different and they can run on many different kinds of fuels .

Some of these cars are called hybrids(混合动力). They can run on different kinds of fuels . One kind of them runs on a special fuel cell which is filled with a gas called hydrogen(氢气). ___小题1:___  They are very clean , and don’t give off bad fumes(烟雾) when they run .
The man who makes fuel cell cars is excited about the technology .__ 小题2:___ Once we use oil up , it will take millions of years for more oil to form. Since gasoline is made from oil , that could be a problem for companies that make traditional cars , and for drives . __小题3:__
Buses that run on hydrogen fuel cell power are being tested on the road . They could become a common form of transportation in the near future

A. The fuel cell cars are also better in another way . B. However, it won’t be a problem for cars that run on fuel cells .. C. He says we will never run out the fuel, but we may run out of oil.

小题4:What do you think of this kind of new cars ? Why ?