41. The number of pilots depends on _.
A. how many hours a plane flies    B. what kind of planes they are
C. the airline companies assign     D. what the pilot likes
42. In order to know the weight of the airplane, the pilots must know_ __.
A. the weight of everything put into the plane
B. the number of people on the plane
C. the weight of the things and people on the plane
D. the importance of the weight
43. What's the Chinese meaning of the word "poisoning" in the passage?
   A. 中毒     B. 难吃      C. 缺少  D.浪费
44. What does the pilot think of the airplane food?
A. Airplane food is more delicious than lobster.
B. The pilot suggests having airplane food instead of lobster.
C. The pilot doesn't like the airplane food at all.
D. Airplane food is as delicious as lobster.
45. What question doesn't the reporter ask in the interview?
A. How  to keep passengers safe?
B. How long do pilots actually spend flying a plane?
C. How to deal with jet lag?
D. How to take breaks during flying.

41. A【解析】由It all depends on if the flight is a short- or long-haul flight.“都取决于这架飞机是长途的还是短途的”可知答案选A。
42. C【解析】由We weigh almost everything put into the airplane and make estimates (估计) according to the number of people on each flight.可知如果要知道飞机的重量，除了要称飞机上所有事物的重量还要知道飞机上的人有多重，故答案选C。
43. A【解析】由he pilots on the same plane are supposed to make different meal choices…“飞机上的飞行员应该吃不同的饭菜……”和only one of them will be sick.“只有一个生病”可知答案选A。
44. D【解析】由Airplane food changes every season and is very delicious可知飞机上饭菜很美味可口，故答案选D。
45. A【解析】通读全文可知记者就是没有问道如何保证乘客的安全，故答案选A。
C
Sitting on a chair all day in school can make anyone want to move around. So, more and more teachers are letting students have a ball. By sitting on exercise balls instead of chairs, teachers find students' posture (姿势) and attention improve.
Dottie Pownall, a fifth-grade teacher in West Virginia, USA, has been using balls as chairs since December 2008. "The students love them", she says. Pownall took a survey of her students. She found that 80% of the students thought sitting on the balls helped them pay more attention to what they were learning.
The teacher, Pisa Witt, felt so strongly about the use of balls as chairs, she started Witt Fitt. This company encourages the use of the balls. And the company educates not only teachers but also students on how to use them. "Our products are used in 24 states, three provinces in Canada, Puert o Rico ('波多黎各) and Japan," says Witt. "Research shows that sitting on the balls makes them sit up straighter. You can slouch (低头垂肩地坐) on a ball," says Witt, "but it feels awful." Because the students are moving, their blood (血液) increases. That carries more oxygen (氧气 to the brain (大脑), so the kids have more energy and can focus longer.
"Furthermore, they're fun." says Pownali.
46. What will happen if a student sits on a chair all day in school? The student will _________.
A. pay more attention to his lessons     B. be fun
C. like to move around                         D. sit up straighter
47. How long has Dottie Pownall used the balls?
A. About three years.       B. Only one year.
C. In 2008.         D. Since he was a fifth-grade teacher.
48. In how many countries are the balls used as the students' chairs?
A. Four.   B. Three.    C. Two.   D. One.
49. Teachers choose balls instead of chairs because sitting on balls helps the kids___________.
A. improve the students' posture and attention         B. slouch on the chairs
C. have fun                                    D. Both A and C are correct answers.
50. Which is better for kids to study in class, sitting on a chair or sitting on a ball?
 A. Sitting on a chair.     B. Sitting on a ball.
C. They are the same.    D. We don't know.
【主旨大意】本文是一篇议论文。通过学生们坐在球上学习的积极作用论证了这一做法的有效性和实用性。
46.C 【解析】 由第一句话Sitting on a chair all day in school can make anyone want to move around.“在学校里坐在椅子上太久了就想四处走动一下。” 可知答案选C。
47. A【解析】 根据第二段第一句中的 since December 2008“自从2008年12月份起”可知到现在大约三年了，故答案选A。
48. A【解析】 通读全文可知这种balls在文中在这四个国家应用：USA, Canada, Puerto Rico ('波多黎各) and Japan，故答案是A。 
49. D【解析】  由第一段的最后一句和最后一段的最后一句可知这种球的功效，故答案选D。
50. B【解析】通读全文可知本文讲的是坐在球上学习的好处，故答案B正和此意，所以答案选B。