首页
登录
职称英语
For centuries men dreamed of achieving vertical flight. In 400 A.D. Chinese
For centuries men dreamed of achieving vertical flight. In 400 A.D. Chinese
游客
2023-08-21
57
管理
问题
For centuries men dreamed of achieving vertical flight. In 400 A.D. Chinese children played with a fan-like toy that spun upwards and fell back to earth as rotation ceased. Leonardo da Vinci con ceive the first mechanical【B1】______,called a "Helix," which could carry man straight up, but was only a design and was never tested.
The ancient-dream was finally realized in 1940 when a Russian engineer piloted a strange look ing craft of steel tubing with a rotating fan【B2】______.It rose awkwardly and verti cally into the air from a standing start,hovered a few feet above the ground,went【B3】______and backwards, and then settled back to earth. The vehicle was called a helicopter.
Imaginations were fired. Men dreamed of going to work in their own personal helicopters. Peo ple anticipated that vertical flight transports would carry millions of passengers as do the airliners of today. Such fantastic expectations were not【B4】______.
The helicopter has now become an extremely useful machine. It【B5】______in military missions, carrying troops, guns and【B6】______ instruments where other air craft cannot go. Corporations use them as airborne offices, many metropolitan areas use them in po lice work, construction and logging companies employ them in various【B7】______ways, engineers use them for site selection and surveying, and oil companies use them as the best way to make offshore and remote work stations【B8】______crews and supplies. Any urgent mission toa hard-to-get-to placeisa likely task for a helicopter.Among their other【B9】______of use:deliver people across town,fly to and from airports,【B10】______ rescue work, and aid in the search for missing or wanted persons. [br] 【B6】
选项
答案
strategic
解析
此处需要名词、形容词或分词作定语,修饰名词instruments。strategic意为“战略的”。
转载请注明原文地址:https://tihaiku.com/zcyy/2945783.html
相关试题推荐
Forcenturies,farmershaveusedwindmillstopumpwater,crushgrainandpe
Forcenturies,farmershaveusedwindmillstopumpwater,crushgrainandpe
Forcenturies,farmershaveusedwindmillstopumpwater,crushgrainandpe
Forcenturies,farmershaveusedwindmillstopumpwater,crushgrainandpe
Forcenturies,farmershaveusedwindmillstopumpwater,crushgrainandpe
Forcenturies,farmershaveusedwindmillstopumpwater,crushgrainandpe
Forcenturies,farmershaveusedwindmillstopumpwater,crushgrainandpe
Forcenturies,farmershaveusedwindmillstopumpwater,crushgrainandpe
Forcenturies,farmershaveusedwindmillstopumpwater,crushgrainandpe
Forcenturies,farmershaveusedwindmillstopumpwater,crushgrainandpe
随机试题
Accordingtotheauthor,thebrandyouuseapparentlyrevealsyoursocialstatus
首席风险官应及时将对期货公司的相关风险核查结果报告给()。A、中国证监会B、中国证监会派出机构C、期货交易所D、期货自律组织B首席风险官发现涉嫌
保险需求的收入弹性
《理想国》是()的代表作。A.柏拉图 B.苏格拉底 C.亚里士多德
距离保护不带方向。
2009年房屋新开工面积是房屋竣工面积的几倍?()A.3倍 B.1
信赖保护原则是行政法的一项基本原则,是指政府对自己作出的行为或承诺应守信用,不得
某期货交易所的会员李某,在3月17日的交易中买入了大量的大豆期货合约。合约的保证
早期固有免疫应答发生于A.感染0~4h B.感染后24~48h C.感染96
编制各级国土空间规划要加强协调性,强化()的基础作用。A.详细规划 B.相关专
最新回复
(
0
)