阅读理解。 Airplanes are polluters. They're

问题：

阅读理解。

     Airplanes are polluters. They're as noisy as a rock concert, and send out poisons into the air as well as

dump millions of pounds of carbon dioxide into the atmosphere every year. By 2050, emissions (排放)

from planes are expected to become one of the largest contributors to global warming. 

     That's why researchers at MIT are designing a completely new type of airplane for NASA that will

enable greener airplanes to take flight before 2050.

     The 180-passenger D"double bubble" series was designed to replace the Boeing 737 class aircraft, the

most popular jetliner in the world right now. The design is called a "double bubble" because it uses two

partial cylinders (气缸) placed side by side. Those two cylinders create a wider structure that looks like two

soap bubbles joined together.

     In today's commercial airplanes, air flows directly into the engines located on the plane's wings. That

high-speed air flow drags on the plane, and requires more fuel to overcome the design inefficiency.

     MIT's design changes all that. By moving the engines to the plane's tail, they take in slower moving air

present in the wake of the fuselage (机舱). Less drag means less fuel is needed to get the plane the same

distance.

     Burning less fuel can help passengers' wallet as well as the environment. The environmental implications

of saving energy are as just as clear: the fewer emissions that planes spout into the atmosphere, the healthier

our planet.

     But for passengers, we still have a couple decades to wait before any of these planes make it onto the

runway. NASA's goal is to make sure the planes that MIT has designed can take off by 2035.

1. The best feature of the double bubble flight is that _____.

A. it will make no noise

B. it will hold more passengers

C. it is designed to save fuel

D. it needs no runways to take off

2. Which of the following is NOT true according to the text?

A. Emission from planes are contributing the most to the global warming

B. Airplanes are very noisy for the environment

C. MIT's new design will save passengers' money

D. It's expected that NASA's goal will be realize by the year 2035.

3. What's the main idea of the text?

A. Here is Boeing 733's terminal

B. Researchers are designing greener aircraft

C. Passengers will enjoy lower prices

D. Airlines attract passengers with new planes

4. The passage will come from a ____. 

A. News report

B. Science fiction

C. Travel diary

D. Business magazine