The first great invention was one that is still very important today -the wheel. This made it easier to carry heavy things and to travel a long distance. For hundreds of years after that there were few inventions that had as much effect (作用) as the wheel. Then ...
The legend of America's X-planes was born in the mid-1940s and flourished till the 1960s, when rocket planes flew to the edge of space. Flights by cutting-edge aircraft like the X-1 and X-15 paved the way for the eventual triumphs of the Apollo programme and Neil Armstrong's first ...
Sign me up at the Embry-Riddle Seaplane School, out on the causeway to Miami Beach, in the 1930s. There are pontooned Piper Cub airplanes and all the fresh orange juice you can drink. The airplane ramps plunge into blue Biscayne Bay, the official school attire is "a tan and shorts,"...
In the early 1800s,the world started to change.There was little unknown land left in the world.People didn't have to explore much any more.They began to work to make life better. In the second half of the 19th century,many great inventions were made.Among them we...
GM's history doesn't involve just cars and trucks. The company also was involved heavily in rail transportation . . . 1930:GM acquired Winton Engine and Electro-Motive Engineering. 1934:Burlington Zephyr used GM diesel in Denver-Chicago dash. ...
Since 1971 this rural Blakesburg, Iowa, grass strip has been the home of the Antique Airplane Association and its annual Labor Day weekend fly-in. Last year nearly 400 aircraft—most built in the 1930s and 1940s—assembled here, on 177 acres of rolling pasture with corrugated-metal buildings...
In the 1800s it was discovered that radio waves could be reflected from objects.But scientists did not make great advances in radar research until the 1930s,when the world was threatened by war.(2)___ It has been used widely in almost every conflict since then. Echoes make it possible...
You've probably heard that you're far more likely to die in a car accident than you are in a plane crash — and that's a fact.According to the National Safety Council, there were 39,107 car crash deaths in the United States in 2019. That same year, there were257 deathsfrom commerci...
aThe first part of the 20th century saw more great inventions. The helicopter in 1909. Movies with sound in 1926. The computer in 1928. And jet planes in 1930. This was also a time when a new material was first made. Nylon came in 1935. It changed the kind of clothes people wear.[...
根据前句But scientists did not make great advances in radar research until the 1930s, when the world was threatened by war表示"但直到20世纪30年代,当世界受到战争威胁时,科学家们才在雷达研究方面取得重大进展",可知表示"在第二次世界大战期间,许多国家有效地使用了雷达"的选项E符合前后的语境,war是提示...