阅读短文，判断下列句子与短文内容是否相符。

    I lived in a village ten years ago．There were no buildings．There were no cars．There was a small school near my village．I went to school on foot．People couldn't use the Internet．We often climbed mountains and went fishing．Now there are many new buildings．There is a new school near the village．Children go to school by bus．People often play computer games at home．

如图所示，将一把钢尺紧按在桌面上，一端伸出桌边，拨动钢尺，听它振动发出的声音。改变钢尺伸出桌边的长度，再次用力拨动，使钢尺两次振动的幅度大致相同，听它发出声音的变化。这个实验用来探究  （     ）