结束“文化大革命”十年内乱的标志是（    ）

    People and animals live in the same world. We should keep the balance（平衡）b____ people and animals. If the balance is destroyed，there will be bad result to both people and animals. Wild animals are friends of people. We have to p____ them， or there will be no wild animals in the future. Now we know that there are  n____ 2，000 nature reserves(自然保护区) in China

    There is a black and white animal l____ in China. It is always known as the national treasure(国宝) of China. Everyone knows it is c____ Giant panda. Now there are f____ pandas than before. Most of them live in Sichuan and Gansu Provinces. There are also some other rare animals in China. H____， the n____ is becoming smaller and smaller than before. So people should try t____ best to help these animals. They are in d____ of disappearing from the world.

大米中铁含量极低，科研人员通过基因工程等技术，培育出了铁含量比普通大米高60%的转基因水稻，改良了稻米的营养品质．如图为培育转基因水稻过程示意图．

小梅同学测定标有“2.5V”灯泡的额定功率的实验，所用灯泡的电阻大约10Ω左右，滑动变阻器的最大阻值50Ω．