如图是某个二倍体雌性动物体内的细胞分裂示意图（局部），三个细胞均来自于同一个动物个体，下列有关说法正确的是（　　）

青色的生虾煮熟后会变成红色．一些同学认为这种红色物质可能就像酸碱指示剂一样，遇到酸或碱会发生颜色变化．就这些同学的看法而言，应属于科学探究中的（　　）

与原尿相比，尿液中不含葡萄糖，主要原因是（　　）

25℃、101kPa下：①2Na(s)+O₂(g)=Na₂O(s)　△H = -414kJ·mol^-1
②2Na(s)+O₂(g)=Na₂O₂(s)　△H = -511kJ·mol^-1
下列说法正确的是（   ）

阅读下列短文，从每小题的三个选项中选出最佳选项。B
    Water comes from the sea, the rain and the tap. Animals, plants and human beings all need water. It is important for our daily (日常的）life. We use water to wash clothes and vegetables. We use water to cook food, make drinks, wash our face and so on. Firemen use water to put out fires. Fanners use water to grow crops. Water is useful. We mustn't waste (浪费）water. We must save water. Turn off the tap when you are brushing your teeth. Don't take a shower too long. Use the same water many times.