阅读下面短文，掌握大意，从每小题所给的A、B、C、D四个选项中选出最佳选项。
A student walks into the teacher's office with his heavy schoolbag slowly and looks worried. "What's happening?" the teacher asks. He tells a lot of small things that make him really unhappy. Then the teacher stops working and decides to do something to help the little boy.
He asks the student to get a glass of water and some salt* from a box. The teacher asks the student to put the salt into the glass of water and drink it.
"How does it taste*?"the teacher asks.
"It doesn't taste good."the student answers.
The teacher doesn't say anything else, but asks the student to get the same amount* of salt and go with the teacher to a nearby lake.
"Put the salt into the lake,"the teacher says. The student does what the teacher says.
"Now, taste the water from the lake,"the teacher says.
The student gets some water from the lake with his hands and tastes, the teacher asks,"How does it taste?"
"Fresh and a bit sweet,"the student answers quickly.
"Do you taste the salt?"the teacher asks.
"No,"the student shakes his head.
The teacher sits beside the student,"The pain* of life is just like salt—no more, no less.
However, how salty it tastes depends* on the container* you put the pain in."
"How do you feel now?"asks the teacher.
The student looks at the teacher with a big smile. He feels much better now.
"Thank you for giving me such a lesson. I think I will never forget the taste of them and learn to be a lake."
