阅读下面的短文，在空白处填入一个适当的词，或填入括号中所给词的适当形式。
An old excellent worker had worked for a house-building company for so longit was time for him to rest. He decided to live a relaxing life with his familyleaving the company. So he told his boss about his plan.
The boss felt sad because his good worker wanted(leave) his company. He asked the worker if he could help the company build just one more house. The worker agreedhis heart was not in his job any more. He didn't spend enough time(choose) good materials（材料）He wasn't willing to spend much time and energy on the last house.
After he finished his job, the boss came to check the house. Then he gave the front door(key) to the worker and said, "This is your house my gift to you for working for the company so well."
The worker was(surprise)! If he had known he was building his own house, he would have built it(careful).
Sometimes we arethe worker. We do something carelessly. We may think the things haveto do with us. However, life is always full of the unexpected. We should try our best to do everything well.