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
2023-08-19
54
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 conceive 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 looking craft of steel tubing with a rotating fan【B2】______. It rose awkwardly and vertically 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. People 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 aircraft cannot go. Corporations use them as airborne offices, many metropolitan areas use them in police 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 to a hard-to-get-to place is a 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] 【B4】
选项
答案
fulfilled
解析
fulfill意为“实现”,与were构成被动语态,因而空格处要填入过去分词形式fulfilled。
转载请注明原文地址:http://tihaiku.com/zcyy/2939162.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
AuniquelaboratoryattheUniversityofChicagoisbusyonlyatnight.Iti
AtachesstournamentinTunisiain1967,BobbyFischer,then24,waspitted
MoreandmoreAmericansarereadingtheirowncreditreport.Creditreportsare
教师组织儿童反复练习一定的动作或活动方式,从而巩固其知识经验、形成简单技能和行为
患者,女,67岁,患2型糖尿病21年。社区护士入户体检时发现下肢水肿,遂到门诊查
"胃家实"是指()A.胃肠实证热证 B.胃肠邪气盛实 C.胃肠燥实证
古诗《鹅》可供儿童吟咏,其作者是( )。 A.蒲松龄 B.李
残疾儿童接受学前教育,并确保其不受教师、同学的歧视,体现了《儿童权利公约》中
某人民检察院渎职犯罪侦查部门接到群众的举报,对某单位领导在一起责任事故中的失职行
妇女的老年期保健不包括A.定期体格检查 B.防治老年期常见病、多发病 C.提
最新回复
(
0
)