阅读理解
A group of old classmates, who have succeeded in their work, got together to visit their teacher. The conversation soon turned to complaining about the stress in work and life. Offering his guests coffee, the teacher went to the kitchen and returned with a large pot of coffee and many cups-china(瓷),plastic and glass, some plain(朴素的）looking,some expensive and some lovely.The teacher told them to help themselves to the coffee.
When all the students had a cup of coffee in hand, the teacher said,“Can you notice all the nice looking expensive cups were taken,leaving behind the plain and cheap ones? While it is normal for you to want only the best for yourselves, that is the source(根源）of your problems and stress.”
“What all of you really wanted was coffee, not the cup, but you went for the best cups and were eyeing(注视)each other's cups.”
“Now think about this：life is the coffee, and the jobs, money and position are the cups. They are just tools to hold life, and do not change the quality of life. Sometimes, we just care about the cups, and we fail to enjoy the coffee. So don't let the cups drive you, enjoy the coffee instead.
H＋＋OH－；DH＞0，下列叙述正确的是
