Hydrogen is a very light gas that can help balloons fly high in the sky.

氢气是一种非常轻气体，可以帮助气球在天空中得很高。

The plane flew overhead, leaving a trail of white smoke.

机头顶过，留下一道白色烟迹。

One is the South American phorid fly.

其中之一就是美国南部。

Flying in an airplane was a new experience for her.

坐机对她来说是件新鲜事。

When the heart is afire,some sparks will fly out of the mouth.

心有什么,嘴总要泄露出来。

The aeroplane was flying a few feet above the sea.

机正在距海面几英尺低空行。

Pilots in the early days of aviation flew by the seat of their pants.

在人类事航空初期, 行员全凭直觉行。

The bullets and cannon-balls were flying in all directions.

子弹和炮弹到处乱。

A great congregation of birds flew overhead.

一大群鸟头上过。

How far is it from here to Nottingham?—Twenty miles as the crow flies.

到诺丁汉有多远?——直线距离20英。

Grandpa’s as happy as a clam helping the children to fly their kites.

祖父帮着孩子们放风筝，乐不可支。

The cork flew off with a pop.

砰地一声瓶塞出去了。

A crow flew crookedly like a shadow over the end of the salt lake.

一只乌鸦像个影子般地在盐湖另一边鬼鬼祟祟地来去。

Always keep food covered to prevent contamination by flies.

时常把食物盖着以防污染。

This is a new program that creates GIF images on the fly.

是一种新程序，能够即时生成GIF图像。

He contrived a new machine for flying.

他设计了一种新式行器。

The biology class studied the generation of fruit flies.

生物班学生研究了果繁殖。

He was a benevolent old man, he wouldn't hurt a fly.

他是一个仁慈老人, 连只都不愿伤害。

The bird caught a bug on the fly.

那鸟在行中捉住了一只昆虫。

The hawk snatched the chicken and flew away.

老鹰叼了小鸡就走了。