在一个不透明的口袋中装有若干个颜色不同其余都相同的球，如果口袋中装有3个红球且摸到红球的频率为$\frac{1}{5}$，那么口袋中球的总个数为（　　）

中国的社会主义运动是从1919年的“五四”运动开始的，至今已经92个年头。历史的发展是有连续性的，不能割裂。在这92年当中，大体上有三个30年。

阅读理解

      Mr. Smith made many tests with different animals and the monkey was the cleverest of all the animals.

      One day Mr. Smith put a monkey in a room. He also put some small boxes in it. In one of the boxes there was some food. "How long will it take the monkey to find the food?" Mr. Smith said to himself. "Let me wait and see." He left the room and waited outside. Three minutes later, he put his eye to the keyhole. What did he see? He saw the eye of the monkey. The monkey was on the other side of the door and looked at Mr. Smith through the keyhole.

填填记记

某中学礼仪队女队员的身高如下表：则这个礼仪队20名女队员身高的众数和中位数分别是（　　）