物质是由大量分子组成的，分子直径的数量级一般是多少？能说明物体内分子都在永不停息地做无规则运动的实验事实有什么例子？在两分子间的距离由r₀（此时分子间的引力和斥力相互平衡，分子作用力为零）逐渐增大的过程中，分子力的变化情况是？

低气压带控制地区一般降水相对较多，而高气压带控制地区降水相对较少．（判断对错）

    Yesterday was Sunday. Tom was at home. He got up at six o’clock in the morning. He had rice for breakfast. At eight he helped his mother do the housework. At nine he watched TV with his father. He cooked fish for lunch. At four in the afternoon he washed his clothes. He went to bed at ten in the evening.

      黔东南苗家吊脚楼是苗族人民智慧的体现。无独有偶，远古时期人们在建造房屋时便能将气候、地理环境等因素综合考虑。以下原始居民中，建造了利于通风防潮的干栏式房屋建筑的是（    ）