下列有关细胞生命活动的分析正确的是（  ）

阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

    Once upon a time, a blind man was sitting at the roadside with a hat by his feet. There was a sign beside him, ____ (say), “I am blind. Please help me.” ____ good many passers-by walked by him, but few of them helped him.

    A creative young man named Tom was going to his office. While walking by the blind man, he stopped ____(see) that the man only had a few coins in his hat. He bent down and put a few of his own coins in the hat. Without asking for the blind man's ____(permit), he took the sign, turned it around and wrote a new message. Then he put the sign by the feet of the blind man, and left.

    ____ (late) that afternoon, when Tom returned to the blind man, he saw the hat ____(fill) with bills and coins. The blind man recognized his footsteps and asked if ____ was he who had changed his sign. He also wanted to know ____ the man had done to the sign.

    Then the young man told the blind man that he ____ (write) something like this on the sign, “It is spring now, but I can't see it.” ____ （hear）what the young man said, the blind man expressed his gratitude to him and went home happily.