题目

It seems that people are gradually losing their smartness as smart phones become increasingly important assistants in their lives. As we rely too much on technology instead of our brains, many people __21_________ (lose) three basic abilities. The first skill __22__________ many people have lost is remembering phone numbers. Because phone numbers are stored in smart phone contacts, there’s now no need to dial a number or look at it again. This is fine until you need to call someone for help, only __23__________ (find) your phone is not around. And some people may also have lost their碳的化学性质思考：（1）千年古画为什么能长期保存？______．（2）写出下列化学方程式：C+O2-______；C+O2（不足）-______；C+CuO-______；说明碳单质具有哪些化学性质？①______；②______．