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
2024-04-14
21
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:https://tihaiku.com/zcyy/3555424.html
相关试题推荐
[originaltext]Today,ChineseAmericansmakeuplessthan1%oftheU.S.pop
[originaltext]Today,ChineseAmericansmakeuplessthan1%oftheU.S.pop
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
JustlikeChinese,Westernersgivegiftsonmanyoccasions,suchas,onbirt
Forcenturiesmendreamedofachievingverticalflight.In400A.D.Chinese
Forcenturiesmendreamedofachievingverticalflight.In400A.D.Chinese
随机试题
ForgettingI.EarlyresearchesHermannEbbinghaus:a
GPSTheGlobalPositioningSystemisaspace
Fordecades,thetelevisionwastheflagshipofanyconsumer-electronicspro
[originaltext]Forthreegroupsofexplorersformedbycollegestudentsand
患儿男,7岁,因发热10天,伴精神萎靡、纳差、腹胀,大便稀糊状,每日2次,经当地
A.绒毛心 B.左心衰竭 C.右心衰竭 D.虎斑心 E.浆液性心包炎肺广
“分式”是初中教学中必不可少的内容,是对分数的进一步抽象。学生已经学习了分数、整
A.马牙 B.螳螂子 C.胎黄 D.胎 E.口疮新生儿两侧颊部各有一脂肪
下列关于消防用电设备供电线路敷设要求的说法中,错误的是()。A.采用矿物绝缘电
机体内环境的稳态是指 A.细胞内液理化性质保持不变B.细胞外液理化性质保持不
最新回复
(
0
)