根据短文内容和所给汉语提示，在空白处写出单词的正确形式，每空限填一词。
When I was sixteen, I met an American teacher. Thanks to him, I got a      (机会) to improve myself.
One day, he wrote a poem on the blackboard and asked us what it meant. Everyone was      (沉默的) in class. Unluckily, the teacher      (选择) me to answer the question.
I said in a   (低的) voice,“Sorry, I don’t know.” I felt uneasy. “Can we be (允许) to answer questions like this?” I thought. To my surprise, he didn’t     (惩罚) me. He gave me a     (宝贵的) lesson.
“ I don’t know,” he said. “It’s a wrong answer. You should at least have some ideas about the question      (虽然) it’s a little difficult. It doesn’t mean that you don’t know. It means you are afraid of making    (错误).” He was right. In fact, I   (很少) spoke out my own opinions. I was afraid of being laughed by others.
After that, I said goodbye to the wrong answer---“I don’t know.” Any answer was better than that one.