Nowadays as the society develops the need of fuel is getting larger and larger. How can we get more and cheaper fuel? One company in New Jersey is developing a special way to get low-cost bio-fuels（生物燃料）from sugar an importang part for getting ethanol (乙醇).

In order to make bio-fuels cheaper the company called Proterro is trying to cut the cost of making sugar. The company is getting photosynthetic microorganisms (光合微生物) to produce large amounts of sugar and it is designing a special way to grow the microorganisms using small amounts of water.

photosynthetic microorganisms such as algae（藻类） are usually thought that it can produce oils. Proterro paid so much attention to making sugar because bio-fuel ethanol is mainly from it and it’s also the starting point for new ways of making other types of bio-fuels.

Today almost all of the sugar for bio-fuels is made from corn or sugarcane（甘蔗），and several companies are trying more ways to make sugar from other plants such as grass and trees. “But we’ve just got the beginning to make bio-fuels; sugar is still expensive ”says Kef kasdin Proterro’s CEO. Only sugar from sugarcane is cheap enough and that can only be grown inexpensively in some places such as Brazil.

51. Why do people try to make bio-fuels?

A. The usual fuels are getting more and more.            

B. Bio-fuels are more important than the usual fuels.    

C. The usual fuels are getting cheaper.

D. Bio-fuels are cheaper than the usual fuels.

52. How are people trying to make bio-fuels cheaper?

A. By making more bio-fuels.         

B. By cutting the cost of making sugar.

C. By getting more photosynthetic microorganisms.

D. By using small amouts of water.

53. Which of the followings might NOT be used to make bio-fuels

A. Wheat         B.Sugarcane         C. Corn             D.Glass

54. How many types of bio-fuels have been made according to the passage?

A. One           B.Two               C. Three            D.Four

55. What do Kef kasdin’s words mean?        .

A.Making bio-fuels has become quite easy.

B. Bio-fuels may be a little more expensive.

C. The company hasn’t cut the cost low enough yet.

D. The company can only get sugar from sugarcane now.