完形填空

先通读下面的短文，掌握其大意，然后在每小题所给的A、B、C、D四个选项中，选出可以填入空白处的最佳选项。

    An old carpenter(工匠)was ready to retire(退休).His boss was 1 to see the good worker leave. He asked the carpenter if he could build just one more 2 . The carpenter said yes, but his mind was not on his work any more. He used poor materials and 3worked on the house. When the carpenter finished his work, the boss  4 the front-door key to him and said, "This is your house. It's a 5 for you."

    What a surprise! If he had known he was 6 his own house, he would have done it differently. Now he had to live in the house he poorly built.

    So it is with us. Sometimes we build our 7 carelessly. At important points we do not try our best. Then with a shame we look at the things we did. We find that we are living in the house we have poorly built 8we don't have a chance(机会)to make it all over again.

    Think of  9as the carpenter. Think about your life. Build it carefully and wisely. It is the only life you will ever build because life is a do-it-yourself project.

    Your life today is the 10 of  your attitudes(态度)and choices(选择)you made in the past. Your life tomorrow will be that of your attitude and choices you make today.

①选择装置并检查气密性．

②称取0.1g的二氧化锰粉末加入容器中．

③量取20毫升溶质质量分数约1%的过氧化氢溶液加入容器中，记录一定时间内收集到的气体体积．

④改变二氧化锰的质量，重复上述实验，记录数据如表．

____派大将卫青、霍去病北击匈奴；西汉抗击匈奴最大的一次战役是 ____；

____ 把昭君嫁给了呼韩邪单于。____在位期间，匈奴再也无力与汉对抗。