一、选择题 (本题共 1 5小题 ,每小题 3分 ,共45分 ,在每小题给出的四个选项中只有一项是正确的 )1 .花粉在水中做布朗运动的现象说明A .花粉分子在做激烈的热运动B .水分子在做激烈的热运动C .水分子之间有空隙D .水分子之间有分子力的作用2 .同一平面内的三个共点力作用在一 First, multiple-choice questions (a total of 15 questions in this question, each question 3 points, a total of 45 points, in each question given only one of the four options is correct) 1. pollen in the water to do Brownian phenomenon Description A. Pollen molecules do intense heat movement B. Water molecules do intense thermal movement C. There is a gap between water molecules D. There are molecular forces between water molecules 2. Three common points in the same plane Force acting at a