题目

In Canada you can find dogs, cats, homes etc, in almost every family. These are their pets. People love these pets and regard them as their good friends. Before they keep them at their houses, they take them to animal hospitals to give them needles so that they won' t cant diseases. They have special animal food stores, though they can get animal food in almost every store. Some people spend around two hundred Canadian dollars a month on animal food. When you visit people's homes, they would be very glad to show you their pets and they are very proud of them. You will also find almost every fa下列四个坐标图分别表示四个实验过程中某些量的变化，其中能正确反映其对应操作中各量变化关系的是（　　） A、向pH=12的氢氧化钠溶液中不断加水B、向接近饱和的硝酸钾溶液中不断加入硝酸钾固体C、加热一定质量的高锰酸钾D、在部分变质的NaOH溶液中加稀盐酸