1 . A professor was teaching his class. All the students were listening to his _______ with great interest. But there was one student whose_______ of mind showed he was in a bad mood.

The professor took notice of this student on the first day but did not say anything. But when this _______ for a week, he asked. “You are _______ in spirits all the time. What is the matter? Have some trouble?”

“Sir, that...” the student said. “... something has happened in my past, _______ which I remain troubled. I don’t know what to do.”

The professor was a(n) _______ good person. He called the student at his house in the evening.

When the student _______ the professor’s house, he was greeted with a _______ welcome. The professor went to the kitchen and started making lemonade for his student. He _______put more salt in the lemonade.

__________ the student had a taste of it, his mouth became sour. __________ this, the professor asked, “Did you not like the lemonade?”

“No, sir, this is not the __________. Just a little more salt in the drink,” the student said. “Now it’s useless. I will throw it away.” The professor __________ his hand to get the glass of drink from the student. But the student refused, saying, “No, sir. If you add more__________, the taste will be fine.”

Upon hearing this, the professor became serious and said, “You are right. That’s what I want to__________. Just as salt cannot be taken out of the lemonade, those bad experiences also cannot __________ life. Adding more sugar can change the taste of lemonade. In a(n) __________way, sweetness has to be dissolved (溶解) in life to forget bad experiences. I want you to take the sweetness in your life into __________ now.”

To his relief, the student __________ him and decided from then on he would not be troubled by the __________.