五、短文填空(本题共10小题;每小题1分,满分10分)
请认真阅读下面短文,并根据各题所给首字母的提示,写出一个合适的英语单词完整、正确的形式,使短文通顺。
[2025镇江市句容市期中]Have you ever known anything about planes? Planes were once 56. m of wood and other materials(材料). However, many things have changed since planes were improved for military use, which really began in 1909. Planes improved in structure(结构) 57. b they had to be able to carry heavy things. And engineers made this come true.
Any progress needs the support of knowledge. With the 58. d of aerodynamics(空气动力学), some engineers came up with new ways to cut through the air smoothly. It was possible for planes to be bigger and fly faster, 59. f and higher.
As planes flew higher, pilots and passengers would have more difficulty in breathing in the thin 60. a. The pressurized cabins(加压舱) were invented in order to 61. s this problem. It made breathing easier in 30,000-foot high sky. Besides, improved radio equipment allowed pilots to receive flight directions from the ground.
There were many improvements in planes in the 1930s. All of them went into building the Douglas DC-3. This twin-engine(双发动机的) transport plane made its first passenger flight in 1936. It could pick up 21 passengers and could fly 62. s. It soon became the 63. m transport plane of the world's major air companies.
In 1958, Pan American World Airways began the first jet(喷气式飞机) service 64. b New York City and Paris using the American Boeing 707 jet. This popular plane made jet travel widely accessible to ordinary people.
Planes have improved many times over the years. But people's needs are 65. a changing. Engineers are working to make even bigger and better planes for the future. It will offer greater comfort to passengers and reduce air pollution.