I've only been there once.

我只去过那里一次。

Where Bucharest now stands, there once was a large, dense forest.

现在的布加勒斯特所在地曾经是一片茂密的大森林。

Jupiter, Saturn, Uranus, and Neptune. Those are the gas giants, the four heavyweights of the solar system. But was there once a fifth?

木星、土星、天王星和海王星。这些都是气体行星，是太阳系的四个重量级。但曾经存在第五个行星吗？

This used to be an agricultural area and we already know that where the main lecture hall now stands, there once were farm house and barn that were erected in the late 1700s.

这曾经是一个农业区，我们已经知道，现在主演讲厅所在的地方曾经有建于18世纪晚期的农舍和谷仓。

There once was a poor farmer who had four sons.

从前有一个贫苦的农夫，他有四个儿子。

I lived there once myself, before I got married.

我从前自己住在那儿，没结婚前。

There once was a beautiful princess whose favorite amusement was a golden ball.

从前有一位美丽的公主，她最喜欢的玩物是一个金球。

There once was a king in a faraway country.

从前在一个遥远的国家有一位国王。

There once lived a rich businessman who had a lazy son.

从前有一个富有的商人，他有一个懒惰的儿子。

My parents seldom go to their hometown. They go there once ten years.

我父母很少回老家，他们十年回一次。

"I have never been there once, really," said Mary suddenly remembering.

“其实，我一次也没去过。”玛丽说，突然想起来了什么。

I have been there once.

我到过那儿一次。

He has been there once or twice.

我去过那里一，两次。

There once lived a pack of wolves in this cave.

在这个洞里曾经住过一群狼。

There once was a little boy who wanted to meet God.

曾经有一个小男孩，他想去见上帝。

“There once was an ugly duckling,” goes the old song.

老歌里唱到：“曾经是一只丑小鸭”。

There once was a concept that rewarded customer loyalty.

曾经有一种对忠实顾客的奖励理念。

There once was a lady who was tired of living alone.

从前有个女人，她厌倦了自己孤单一个人生活。

There once lived a race of huge giants called Titans.

从前，有一个地方住着一族叫泰坦的巨人。

How do I intend to get there once I know what my goal is?

一旦我知道了自己的目标是什么，我要怎样去实现它？

There once was a snail that wanted to buy a Nissan Z car.

有一个蜗牛想买一辆“尼桑z”型号的车。

There once was an evil priest who did not fear God or man.

从前有个邪恶的神父，不敬畏上帝也不害怕任何人。

There once was a nonconformist bird that decided not to fly south for the winter.

曾经有一只不墨守常规的鸟，他决定不飞往南方过冬。

And, there seems to be a lot more cement where there once were grass and trees.

而且，铺水泥的地方也多了很多，那些地方原来是种草和树木的。

There once lived in a town of Persia two brothers, one named Cassim and the other Ali Baba.

从前在波斯的一个城市里住着两兄弟，一个叫凯新，另一个叫阿里巴巴。

There once lived a great warrior. Though quite old, he still was able to defeat any challenger.

从前有一位伟大的武士，他虽然已经年迈，但依然所向无敌。

However, there once was a creature that actually resembled what Bigfoot is supposed to look like.

然而，实际上曾经有一种生物跟大脚怪长得很像。

There once was a marvellous overland escalator in Moscow. At present one may only roam about its ruins.

在莫斯科，曾经有一个令人赞叹的艺术之梯，而今，人们只能对着它的废墟唏嘘不已。