阿司匹林的含量测定：（） A.酸碱滴定 B.非水滴定 C.氧化还原 D.气相色谱 E

根据短文内容和首字母的提示，把所缺单词填写在短文后面的横线上。

Robot s  70  are not just trying to make robots look like people. For example, there are already robots w  71   in factories. These robots look more like huge arms. They do simple jobs over and over again. People would not like to do such jobs and would get bored. But robots will never get bored. In the future, there will be more robots e  72   , and humans will have l73        work to do. New robots will have many different shapes. Some will look like humans, and others might look like snakes. After an earthquake, a snake robot could help look for people under b  74  . That may not seem possible now, but computers, space rockets and even electric toothbrushes seemed i   75    a hundred years ago. We never know what will happen in the future.

应力是反映物体受力程度的物理量。

（6分）某实验小组根据下图所示装置探究燃烧的条件，请回答问题。

（1）检查装置气密性后，燃烧匙中放入少量的白磷，小烧杯内放入适量的碳酸钠粉末，组装好装置。打开弹簧夹，将溶液A缓慢加入到小烧杯内，溶液A是______，一段时间后，______（填写后续实验步骤和现象），关闭分液漏斗的活塞、弹簧夹，然后用凸透镜加热白磷，观察到白磷不燃烧，该实验过程的目的是______。

（2）停止加热，轻轻振荡装置，一段时间后打开弹簧夹，再用凸透镜加热白磷，观察到白磷燃烧，白磷燃烧的原因是______，该实验过程中发生反应的化学方程式为______。

国家在水土流失重点预防区和重点治理区，实行地方各级人民政府水土保持目标责任制和（）。

框架结构的破坏机理是什么？