When Charley got up one morning, he saw the ground deeply covered with snow.

“We must have a path through this ________ ” said his father. “I would make one if I had time. But I must be at the office ________ this morning.” “Do you think you could make the path, my son?” he asked little Charley.

“I? Why, the snow is too ________ !’

“You can try doing it little by little,” said the father, as he ________ for his office.

So Charley got the snow shovel (铁铲) and set to work. But it was ________ work. He got tired.

“I don’t think I can do it, mother,” he said. “A shovelful (满铲) is so ________ , and there is such a heap (堆) of snow.”

“Little by little, Charley,” said his mother. “That snow fell in tiny bits, flake by flake, but you see what a great ________ it has made.”

“Yes, mother, I see,” said Charley. “If I ________ it away little by little, it will soon be gone.”

So he worked on.

When his father came home to dinner, he was ________ to see the fine path.

The next day he gave little Charley a fine blue sled (雪橇), and on it was ________ in yellow letters, “Little by Little.”

Every girl dreams and Lisa is no exception. She once hoped that her dream of _______ a ballet dancer would _______ one day. She worked hard at her ballet lessons and all her teachers believed that she was a good student.

One day, she saw a poster saying that a famous ballerina troupe would be performing in her hometown. Her _______ ran wild. “I must _______ the leader of the troupe and show him my skills!” She said to herself.

When the troupe _______, Lisa put on her ballet outfit and _______ the troupe’s dressing room. When the leader of the troupe entered the room, she came out and introduced _______. She couldn’t wait _______ the leader about her dream.

The leader asked Lisa to dance for him. But halfway through her dance, he stopped her and said, “I’m sorry. You’re not _______!”

Upon hearing this, Lisa ran out of the dressing room. She felt quite ashamed.

Years later, Lisa had ________ dancing. She asked the leader of the troupe ________ he didn’t think her dancing was good enough. He replied, “I say this to ________ of my students.” Lisa said, “But you ruined my life!”

The leader pointed out that he had been impressed with her ________ when she hid in the dressing room just to show him her dancing skills. “But if you had treated ballet ________, you wouldn’t have stopped dancing ________ easily when I told you that you weren’t good enough,” he explained.

Nature is full of great ideas. Mary inventors watch nature for ideas to make some _______ things.

For example, a new type of cane (手杖) was invented to help blind people move around more _______. And the idea behind this invention came from the bat.

Bats make sounds when they fly at night. These sounds can't be heard by people _______ they help bats fly in the dark.

Bats send out sound waves (波) through their mouth or nose when they fly. If these sound waves _______ objects around them, they will be sent back as an echo (回声). The echo tells bats how far away things _______ trees are. It also helps them know _______ to find something to eat.

After watching how bats fly, the scientist who invented the new cane first built a lightweight cane, and then to it he _______ device (装置) that sends and receives the same sound waves as bats do while flying. Finally, he _______ the cane. It worked out!

The cane sends out sound waves. When an echo is sent back, the top of the cane vibrates(震动). This helps the person _______ the cane know how far away an object is. They will also know how big the object is.

The ________ of the cane shows that nature is really where great ideas come from.