This morning, a Virgin Atantin 747 Jumbo Jet became the first commercial airplan

This morning, a Virgin Atantin 747 JumboJet became the first commercial airplane to fly on biofuel. The short flightfrom London to Amsterdam used a blend of 20% babassu(棕榈) oil mixed with 80%conventional jet fuel.

What was really exciting about the flightwas the fact that the engine did not have to be altered in any way for thebiofuel to work While this is a great initial step in trying to reduce CO₂(carbon-dioxide)emissions(排放)from airplanes. there are alot of hurdles (障碍)thatstill need to be overcome.

First and foremost, unlike the normal fuelused to run airplanes (known as Jet A),biofuel freezes at high altitudes. Also,Jet‘A’fuel burns consistently (at the same pace),which means it provides a safeand reliable fuel for long flights--engineers are not sure if biofuel will beable to do the same.

The biggest hurdle to a full biofuel switchis our ability to be able to grow enough crops that can be converted tobiofuel. There are two concerns that scientists have in this matter – the firstis that the land to grow the extra crops will come from clearing more of ourforests and the second is that since it competes with what we eat, the price offood will go up.

However, Richard Branson of VirginAirlines, envisions that if biofuel starts to replace oil on a greater basis,it will be manufactured from algae（藻类）produced in sewage treatment plants, not from food sources.

Birgin Airlines is not the only one tryingto look for alternative fuel sources. Earlier this year, an Airbus A380 usedanother alternative fuel－a man-made mix of gas-to-liquid, in one of its four engines. Theflight was tested by Rolls Royce (manufacturer of jet engines), in partnershipwith Shell (an oil company). Rolls Royce is also working with Air New Zealandon a similar project.

While a complete switch to alternative fuelmay take years, it is very encouraging to see airlines, oil companies andairplane manufacturers all coming together to try to make it happen!

1.．Why does Virgin Airlines try to replace normal fuel with biofuel?

2.．Which is NOT true for a full biofuel switch of airplanes?

A Biofuel cannot run for longflights.                  

B．Biofuel cannot work at high altitudes.

C．Man has not enough land to grow extra crops for biofuel. 

D．It’s not easy for sewage treatment plants to manufacture biofuel.

3.．One of the hurdles to be overcome for a full biofuel switch is to          .

4.．We can infer from the last paragraph that          .

5.．Which of the following can best serves as the title of this passage?

试题答案

【答案】

1.C

2.D

3.B

4.A

5.B

【解析】

试题