贝加尔湖

波莉在第五天早晨醒来。世界变成了一片水域。

Polly woke on the fifth morning. The world had become water.

火车正在沿着贝加尔湖行驶。湖水占满了整个窗户。水是深邃而完美的蓝色。

The train was running along Lake Baikal. The lake filled the whole window. The water was a deep, perfect blue.

渔夫伊戈尔正拿着笔记本站在窗边。

Igor, the fisherman, was at the window with a notebook.

“贝加尔湖，”他说，“是世界上最深的湖，深达1642米。它也是最古老的湖，有2500万年的历史。”

"Baikal," he said. "It is the deepest lake in the world. 1,642 metres deep. It is also the oldest lake. 25 million years old."

湖水清澈见底，波莉能看到浅水处湖底的岩石。

The water was so clear that Polly could see rocks on the lake floor in the shallow places.

“它储存了地球上23%的非冰冻淡水，”伊戈尔说，“比北美的所有五大湖加起来还多。”

"It holds 23 percent of all the fresh water on Earth that is not frozen," Igor said. "More than all the Great Lakes in North America together."

火车在斯柳江卡站停下。伊戈尔下了车。他用两根手指握了握波莉的翅膀尖。“三天的捕鱼，然后回家。”他挥了挥手就走了。

The train stopped at Slyudyanka station. Igor got off. He shook Polly's wing tip with two fingers. "Three days fishing. Then home." He waved and was gone.

火车沿着湖又行驶了三个小时。一群贝加尔湖海豹浮出水面。它们是世界上唯一的淡水海豹。

The train ran along the lake for three more hours. A group of Baikal seals came up to the surface. They are the only freshwater seals in the world.

波莉想着在她下面有多少水。贝加尔湖里住着一种小粉红色的虾，它负责保持湖水清洁。它已经做了这个工作两千万年了。

Polly thought about how much water was below her. A tiny pink shrimp lives in Baikal. It keeps the water clean. It has been doing this job for 20 million years.