判断下面的说法是否正确。

读课文《杨氏之子》，“梁国杨氏子九岁，甚聪惠。”这句话点明了文章要讲的主要人物以及人物的特点，有总起全文的作用。

如图所示，将一把钢尺紧按在桌面边缘，一端伸出约为尺长的一半，拨动钢尺，听它发出的声音，并观察它的振动情况．然后减小钢尺伸出长度约为尺长的 $\frac{1}{4}$ ，用相同的力度再次实验，得到的结论是发现振动的频率变____，发出声音的____变高．

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.