题目

Fast food is becoming more and more popular in China, especially among children and teenagers. There are several reasons 66          its popularity. First, it is very convenient and 67            a lot of time. You just go into a fast food restaurant, order your food, and your food is ready  68              . Second, you can either eat it there or 69            it away. Third, the environment of fast food restaurants is both clean and 70              （comfort）. Fourth, excellent service 71                为了研究物质某种特性，某同学测得四组数据，填在列表中：实验次数物体质量（g）体积（cm3）密度（g/cm3）1铝块154202.72铝块2108402.73松木1108216①4松木210200.5（1）将上表①处填写完整．（2）比较第1、2两次实验数据，可得出结论：同一种物质，它的质量跟它的体积成    ．（3）比较第2、3两次实验数据，可得出结论：质量相同的不同物质，体积    ．（4）比较第1、4两次实验数据，可得出实验结论是    ．