1What does NASA plan to do?

 A.To build one more Hyper-X aircraft．  B.To carry out three more Hyper-X experiments．  C.To make the aircraft fly higher and longer．  D.To test another hypersonic flight at 10 times the speed of sound  

2What does Werner J．ADahm say about the Hyper-X test flight?

 A.It was unsuccessful because it lasted only 1 seconds．  B.It is a very important event in developing very fast airplanes．  C.It allows people to fly at an altitude of 100,000 feet．  D.It can transport cargo quickly and cheaply to outer space  

3Which of the following is NOT true of the scramjet engine?

 A.It has been used on passenger planes．  B.The air it breathes does not put out the combustion flames．  C.It works at speeds greater than five times the speed of sound  D.It goes as fast as a rocket．  

4What kind of engine did the Hyper-X use?

 A.A jet engine that carries its own oxygen supply．  B.A jet engine that uses no oxygen．  C.A scramjet engine that doesn't carry its own oxygen supply．  D.A rocket engine that carries its own oxygen supply．  

5The Hyper-X broke the record because

 A.it was the first air-breathing jet plane  B.it flew along the equator．  C.it traveled at the speed of sound  D.it reached a speed of about 5, 000 miles per hour，   2、(二)Stop Eating Too Much "Clean your plate!" and" Be a member of the clean-plate club! " just about every kid in the US has heard this from a parent or grandparent．Often, it's accompanied by an appeal：" Just think about those starving orphans（孤儿）in Africa!" Sure，we should be grateful for every bite of food．Unfortunately, many people in the US take too many bites．Instead of staying "clean the plate", perhaps we should save some food for tomorrow．According to news reports, US restaurants are partly to blame for the growing bellies（肚子）．A waiter puts a plate of food in front of each customer, with two to four times the amount recommended by the government，according to a USA Today story．Americans traditionally associate quantity with value and most restaurants try to give them that．They prefer to have customers complain about too much food rather than too little．Barbara Rolls，a nutrition（营养）professor at Pennsylvania State University，told USA Today that restaurant portion sizes began to grow in the l970s, the same time that the American waistline（腰围）began to expand.Health experts have tried to get many restaurants to serve smaller portions．Now，apparently，some customers are calling for this too．The restaurant industry trade magazine QSR reported last month that 57 percent of more than 4,000 people surveyed believed restaurants served portions that were too large；23 percent had no opinion；20 percent disagreed．But a clo