There once lived a young crow in the countryside. One summer, there was no rain and it was very hot. The crow was very thirsty, but he couldn't find any water.
"How can I survive?" he thought. "I must have water or I'll die!"
Just then he saw a farmhouse. Outside the house, there was a vase with some water at the bottom. He tried to drink, but he couldn't reach the water inside.
The young crow didn't know what to do. He leaned against the vase and cried.
"Will somebody please help me?" sobbed the crow. He cried and cried, but nobody heard him. Finally, he dried his eyes and stood up.
He tried knocking over the vase, but it was too heavy. Then he tried breaking it, but he wasn't strong enough. Finally, he had a good idea. He began dropping stones into the vase. The water slowly rose to the top. At last, the crow could drink.
"What wonderful water!" said the crow. "I'm glad that I didn't waste all my time by crying. Thinking is much better than crying!
5.sob v. 啜泣
（someone）must +v. or…（某人）必须……, 否则……
must 之后要接原型动词，表示必须（做某事）的意思，跟have to 意思相近。
You must finish your homework tonight.
have to 可指受到外在条件或约束影响而必须作某事。
I have to go now. Jim is waiting for me.
You must study hard or you’ll fail.