A

    There were many people on a bus. An old man ____(look) here and there. He wanted to find ____ empty seat. Then he saw one and went to it. A small bag was on the seat. And a young man was beside it.

    "Is this seat empty?" asked the old man.

    "No, it's ____ an old woman. She went to buy some bananas.” said the young man.

    "Well, let me sit here, please. I'll leave here when she ____(come) back, "replied the old man.

    After a few minutes, the bus started. "The old woman ____(not come), but her bag is here. Let me give her the bag. "Then the old man threw the bag out of the bus window.

    The young man jumped up and shouted, "Don't throw! It's my bag!"

世界上最长的山脉和最高的山脉分别是（   ）

下列各句中，划线成语使用不恰当的一项是（   ）

已知反比例函数y=（3m﹣1）$x^{m^2-2}$的图象在第二、四象限，求m的值．

如图是缩手反射的反射弧结构模型图，下列说法错误的是（　　）