阅读下列短文，从每题所给的四个选项（A、B、C和D）中选出最佳选项。
Are you sorry for not traveling during the National Day? If you stay at home at that time, I think you are very lucky. Why? Because there are too many people everywhere. In many places of interest in China, it's too crowded to do anything.
Look at the picture. It was too crowded on the Great Wall on October 1st, 2015. You even couldn't take photos for you or your friends. All what we could see were people. It was reported that there were about twenty people every meter on the Great Wall. My friends told me they could see nothing but many people on the Great Wall. "We couldn't walk if the people in front of us didn't walk," he said. He showed us a photo on the Great Wall. In the photo, we hardly found him out, there were too many people.
So some people give the advice that we should not have the gold week any more. But other people say no about this advice. What's your idea of it? Are you sorry now for not traveling during the gold week? I love staying at home more than traveling next National Day.
溶液时，图12-5所示的电解变化曲线合理的是
