写作思路：根据题目要求，写出《曹冲称象》的主要内容。

In ancient times, there was a man named Cao Cao.

古时候有个叫曹操的人。

Others sent him an elephant, he was very happy, with his son and officials to see.

别人送他一头大象，他很高兴，带着儿子和官员们一同去看。

The elephant is tall and big. Its body is like a wall and its legs are like four pillars.

大象又高又大，身子像一堵墙，腿像四根柱子。

The officials looked and talked: "how heavy is such a big elephant?"

官员们一边看一边议论：“这么大的象，到底有多重呢？”

Cao Cao asked: "who has a way to weigh this elephant?"

曹操问：“谁有办法把这头大象称一称？”

Some said, "you have to build a big scale and cut down a big tree to make a scale."

有的说：“得造一杆大秤，砍一棵大树做秤杆。”

Some said: "it's not good to have a big scale. Who has the strength to lift this big scale?"

有的说：“有了大秤也不行啊，谁有那么大的力气提得起这杆大秤呢？”

Cao Cao shook his head.

曹操听了直摇头。

Cao Cao's son Cao Chong is only seven years old.

曹操的儿子曹冲才七岁。

He stood up and said, "drive the elephant to a big ship and see how much it sinks. Draw a line on the side of the ship along the water. Then he drove the elephant ashore and loaded the boat with stones until the boat sank to the place where the line was drawn. Then weigh the stones on the boat. The weight of a stone is the weight of an elephant. "

他站出来，说：“把大象赶到一艘大船上，看船身下沉多少，就沿着水面，在船舷上画一条线。再把大象赶上岸，往船上装石头，装到船下沉到画线的地方为止。然后称一称船上的石头。石头有多重，大象就有多重。”

Cao Cao nodded with a smile.

曹操微笑着点一点头。

He asked people to do as Cao Chong said. As expected, he weighed the elephant.

他叫人照曹冲说的办法去做，果然称出了大象的重量。