设f(x)=3^x+3x-8，用二分法求方程3^x+3x-8=0在$x\in \left(1,2\right)$内近似解的过程中得f(1)<0,f(1.5)>=,f(1.25)<0，则方程的根落在区间（     ）

（1）当要研究的物理量不易直接测量时，都要想办法把它们的大小间接表示出来．例如：在探究摩擦力与什么因素有关的实验中（如图所示），用弹簧测力计水平拉着木块在水平桌面上做 ____运动时，通过读取弹簧测力计上的示数可间接知道摩擦力的大小，这是利用了 ____原理．若实验中拉着木块由铺有毛巾的木板运动到光滑的木板上，则木块受到的摩擦力将 ____（选填“变大”、“变小”或“不变”）．

（2）日常生活中，矿泉水瓶盖上的竖条纹是利用了 ____来增大摩擦，让我们更容易打开盖子．

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    I'm an Chinese girl. My name is Rose. I have a brother. His name is Tom. Tom and I are in the same school. I often go to school by bike. Tom usually⑴w__________ to school. We both(两个都) have lunch at school and we like Chinese food very much. After school， Tom always plays basketball with his classmates. ②I always speak Chinese because I like Chinese best. I go home at about five o'clock in the afternoon. But Tom goes home late， at about a quarter past seven. My parents are both teachers. They teach for many years in Beijing. We like China very much.

乌贼遇到敌害，会喷放墨汁，这一现象属于生物特征中的（　　）

在兰州交汇的铁路干线有（　　　　　）