It was Sally's birthday, and Mother had made her a cake with even candles on it. 莎莉的生日到了，妈妈给她做了一个蛋糕，上面还放了蜡烛。

Mother, Sally, and Nan went to the beach for a picnic and took the birthday cake with them. 妈妈、莎莉和南带着生日蛋糕去沙滩野餐。

The two girls took off their shoes and stockings and waded in the water. 两个女孩脱下鞋袜，在水里蹚水。

They dug caves and built castles in the sand. 她们还挖洞，在沙滩上建城堡。

Soon Mother was ready to cook dinner. 不久妈妈准备做饭了。

So Nan and Sally ran up and down the beach, picking up dry sticks. 于是南和莎莉在沙滩上跑来跑去，捡干树枝。

Then they piled the sticks together to make a fire, and Nan called Mother to light it. 然后，她们把树枝堆在一起生火，南叫妈妈来点火。

"Nan," said Mother, "these sticks will not burn. 妈妈说：“南，这些树枝烧不起来。

They are so close together that no air can get between them. 它们挨得太近，中间没空气了。

You must spread them out. Fire needs air to burn. Let me show you something." 你必须把它们摊开。火需要空气才能燃烧。我给你示范一下。”

Mother took a candle from Sally's cake and lighted it. Then she set it up in the sand. 母亲从莎莉的蛋糕上拿了一支蜡烛点着，然后把它放在了沙滩上。

"Now," said Mother, "get me the glass jar we brought for water." 妈妈说：“现在，把我们带来的盛水玻璃罐给我。”

She put the jar over the candle, 她把罐子放在蜡烛上，

and the candle flame changed slowly from yellow to blue. Then it went out. 蜡烛火焰慢慢从黄色变成了蓝色，然后熄灭了。

"No air can get through the glass jar," said Mother. “没有空气能进玻璃罐里，”妈妈说，

"After the fire burned all the air inside the jar, it couldn't ge any more air, and the flame went out." “火把罐子里的空气烧光后，又得不到更多的空气，就熄灭了。”

Nan made another pile of sticks. 南又堆了一些树枝。

This time she spread the sticks so that plenty of air could get between them. 这次，她把树枝散开，以便中间有足够多的空气。

When the fire was lighted, it burned quickly. 当她点火时，它燃烧得很快。

"We can put this fire out if we pour sand on it," said Mother. “如果我们在上面倒沙子，就可以把火扑灭。”妈妈说，

"The sand will keep air from the fire." “沙子可以隔离火和空气。”

"May I try it now?" asked Nan. 南问：“我可以现在试试吗？”

"Yes," said her mother. "But be careful!" “当然，但要小心！”妈妈说。

Nan poured sand on a burning stick, and the flames went out. 南把沙子倒在燃烧的树枝上，火焰熄灭了。

"Before we leave, we will put out our fire by pouring sand on it." said Mother. “我们离开前，要用沙子把火熄灭。”妈妈说。

While Mother was cooking the dinner, Sally lighted the seven candles on her cake. 妈妈做饭时，莎莉点燃了蛋糕上的七根蜡烛。

How pretty they looked! 它们看起来多漂亮啊!