MnO₂常用于实验室和电池工业，回答下列问题：

（1）MnO₂主要存在于软锰矿中．写出舍勒用软锰矿制取Cl₂的离子方程式____ ．

（2）检验溶液中Mn²⁺的方法为：向待测溶液中加入硝酸，无明显现象；继续加入难溶于水的NaBiO₃ （还原产物为Bi³⁺），溶液呈紫红色，写出反应的离子方程式____ 　．某生取实验室制备Cl₂后的冷却澄清溶液，依次加入硝酸、少量NaBiO₃，发现溶液变为紫红色后立即褪去，简述紫红色褪去的原因____ ．

（3）甲、乙分别为工业制备电解锰和电解MnO₂的原理图．

①甲池中阳极放出的气体是____ ．

②要配制乙池的电解质溶液250mL，需要称取MnSO_{4____} g．

③写出乙池中反应的化学方程式____ ．

（4）丙所示电解池，通电后阴极和阳极上分别得到单质Mn和MnO₂．

①写出丙池电解总反应的离子方程式　____ ．

②与甲、乙比较，丙的突出优点是____ ．

（5）上述方法制备的MnO₂常用于制造电池．写出碱性锌锰电池放电时的总反应式____ 　．

用直尺和圆规作一个角等于已知角得到两个角相等的依据是____ 

    As darkness fell, hundreds of people in the Swiss village left their houses. They were staring（凝视）1at the mountain top in the distance. It was covered with 2 beautiful and dangerous.

    The huge mountain is called Matterhorn. Mountain climbers had 3the top, using the southern route. But no one had ever dared（敢）to try a winter climbing up the 4 side. But now one man was daring to try the 5route. He was Walter Bonatti, a great mountain climber from Italy.

    For two days he had climbed. The village people had watched him anxiously(焦急地). Now they were waiting to see his signal（信号）. If he planned to 6 the next day, he would light a green signal. A red light would mean that he was turning back.

    A tiny green light7 high on the mountain side. Bonatti was not giving up! The people8.

    The next day he continued his way upward. He was so lonely and so 9! But he would not give up. Again that night he lit the10 light.

    In the morning, Bonatti 11. He couldn't see the top, but he knew he was 12 there. Though the climb was painful, he moved up.

    Bonatti had spent months13 for the climb. Was the training enough? Did he have the strength and skill to climb to the top?

     He was finally at the top! News about his 14 was radioed to the world.

    The trip down the southern route was easy. He was warmly welcomed in the village. He had done the"15", and would be well remembered as a climber of all time.