A:甲图中:小明的书包背带比较宽,这样可以减小对肩部的压力
B:乙图中:小丽用吸管能把饮料吸入口中,说明她对水产生了压力
C:丙图中:压路机轮子的重量就等于对路面的压力,说明压力就是重力
D:丁图中:洗手池的回水管做成U型,和常见的卫生间地漏工作原理是相同的
Introduction of a Band
Band name
The new band is called ____.
Country
The band was set up in ____.
Members
There are four people in the band and they are all ____.
Kind of music
More and more people love to listen to their ____.
The reason why people like them
All of their music sounds comfortable and make people ____.
构建知识结构是学习历史的有效方法之一。 这是某学习小组在历史课上设计的知识卡片。 据此判断该历史课的主题是( )