小丽在探究碱的化学性质时，将稀盐酸滴入到氢氧化钠溶液中，意外地看到有气泡产生，她认为氢氧化钠溶液已经变质了．用化学方程式表示氢氧化钠溶液变质的原因：____．
【提出问题】变质后的氢氧化钠溶液中的溶质是什么？
【猜想假设】小丽对变质后的氢氧化钠溶液中的溶质成分做出了两种猜想：
猜想一：____；猜想二：____．
【实验设计】为验证上述猜想哪个正确，小丽设计了如下方案：取少量氢氧化钠溶液样品于试管中，滴加几滴无色酚酞溶液，观察溶液颜色变化．小红认为小丽的实验方案不合理，理由是：____．
【实验与结论】小红另外设计并完成了实验，请你帮她填写下面的实验报告：

下列地质灾害主要由外力导致的有         (   )

C

    Once upon a time，there was a king who had gone to visit neighboring kingdoms．He was gifted a pair of baby parrots by the king of the last kingdom where he was visiting．They were the most beautiful birds that he had ever seen．so，after returning to his kingdom，he called for a bird trainer and asked him to train parrots．

    The king also set up a place in the palace garden for the parrots．He often looked at them from his palace window．As time passed，one day the trainer came to the palace and told the king that though one of the parrots was flying high in the sky，the other one was not moving from its branch since the day it had arrived．

    When hearing this,the king summoned the best trainer from all his land and the nearby kingdoms．They came quickly and tried their best, but none of them could make the parrot fly!He even asked his courtiers to try to find a good way to make the parrot fly but they all failed．The parrot was not moving from his branch at all．Finally，after trying everything，the king thought to himself："Perhaps I need someone who may be more familiar with natural habitat．"He asked his courtier to get a farmer from the countryside and take him to the parrot to see if he could understand the problem with the parrot．

    The next morning，the king was surprised to see the parrot flying high above the palace gardens．He asked his servant to call that farmer to meet him．The servant quickly went and found the farmer．The farmer came and stood before the king．The king asked him，"How did you make the parrot fly?" With his hands folded with respect，the farmer said to the king，"It was very easy．I just cut the branch where the bird was sitting．"

制备细胞膜时，通常选取的细胞和处理的方法分别是（      ）