阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空。

    One day, a lobster(龙虾) met a hermit crab(寄居蟹)in the deep sea. They stopped ____ (swim) and began to have a talk with each other.

    The lobster ____ (take) off his hard shell and showed his lovely and soft body. When the hermit crab saw the lobster take off the shell, ____felt surprised. He shouted at the lobster and wanted to stop the lobster.

    "Hey!" said the crab. “____ are you talking off your shell? The shell is ____ (use) and it can protect you. Now you take off your shell. Big fish may eat you. You may also knock against a rock. Don't be silly. Please put ____ your shell again. Or you will have to ____ (payment) a heavy price for what you did."

    “____ (thank) for your reminding, hermit crab! But we take off our shells in order ____ (grow) better. ____we are afraid to take off our shells, then we can't move forward in life," answered the lobster.

    The hermit crab thought it over and understood what the lobster said.