化学学习小组做实验时记录了下列实验现象，其中正确的是

现有常温时pH＝1的某强酸溶液10mL，下列操作能使溶液的pH变成2的是

光纤可作为光传导工具，其传输原理是光的全反射．按照纤芯折射率分布情况可以分为突变型光纤和渐变型光纤，突变型光纤的纤芯的折射率是均匀的，而渐变型光纤的纤芯的折射率不均匀．下列关于这两种光纤说法正确的是（　　）

    I'm Lucy. I have a happy family. There are four people in my family. My birthday is on January 1st. It's New Year's Day, too. My family and I will have a big dinner on that day. I have a little brother. He is four years old. His birthday is in winter. It's very cold but we can make a snowman. My mother's birthday is in March. My father's birthday is in March，too. We can plant trees and fly kites.