阅读理解
Ben was hoping for a video game for his birthday. He also wanted a board game. And he wanted some CDs too.
He got the board game and some CDs, but what was in the last package (包裹)? It was from his sister. He slowly opened the package. It didn't feel like a video game.
It was a purple sweater. Purple was Ben's least favourite colour. He smiled and thanked his sister nicely, but he didn't want to wear that sweater. He couldn't wear purple!
He quickly put the sweater away in his room. Then he ran off to play the new board game with his family.
The next day, Ben's mother asked him about the sweater.
"Why don't you wear your purple sweater today?" she said. "Your sister made it just for you!"
"I am not cold," Ben said without thinking. In fact, he was lying. He shivered (发抖) all day.
Then one day they were going out to dinner as a family. Ben's mother asked him to wear the sweater again. "I don't want to wear it. I hate (讨厌) purple," he said.
"Ben," said his mother, "I know it's not the nicest sweater in the world, but think about how important Karen is to you. You know she will be very happy if you wear it to dinner."
Ben walked slowly to his room. He knew his mother was right. He wore the sweater to the restaurant. His sister smiled all night.
轴正方向传播，图1是
时的波形图，图2是波中某质点
振动位移随时间变化的振动图线（两图用同一时间起点），下列判断正确的是:
