单选题 Life is difficult.
But life is no longer difficult once we truly understand and accept it.
Most do not fully see this truth. Instead they complain about their problems and difficulties as if life should be easy. It seems to them that their difficulties represent a special kind of suffering especially forced upon them or else upon their families, or even their nation.
What makes life difficult is that the process of facing and solving problems is a painful one. Problems depending on their nature cause us sadness or loneliness or regret or anger or fear. These are uncomfortable feelings, often as painful as any kind of physical pain. And since life causes an endless series of problems, life is always difficult and is full of pain as well as joy.
Yet, it is in this whole of solving problems that life has its meaning.
Problems are the serious test that tells success from failure. When we desire to encourage the human spirit, we encourage the human ability to solve problems just as in school we set problems for our children to solve. It is through the pain of meeting and working out problems that we learn. As Benjamin Franklin said, "Those things that hurt, instruct." It is for this reason that wise people learn not to fear but to welcome the pain of problems.

单选题 The passage begins with a short sentence probably in order to ______.

单选题 According to the passage, which of the following is true?

单选题 Why do we always set problems for school children to solve?

单选题 The sentence "Those things that hurt, instruct." means that ______.