“身体分为头胸腹，两对翅膀三对足，头上一对感觉须，骨头长在肉外头”描写的是____ 的特征。

______ his pocket money, Bill bought many books for the poor children.

    Mrs．Marks bought a printer yesterday．She was h____ because she could print anything she wanted at any time．H____,after about an hour, she was angry because she couldn't print the color blue．All the other c____ printed free, except(除了)blue，which was very unusual．

    She d____ to call the after-sales service department(售后服务部)to help her solve the problem．David answered the phone．He t____ everything he could think of to help Mrs．Marks．He asked her to reinstall(重新安装) the program，to reboot (重新启动)the computer and to turn the printer on and off．N____ of these things helped．

After hours of trying，the problem s____wasn't solved．Finally, David asked Mrs．Marks if he could go to her h____and try to solve the problem in  person．Mrs．Marks agreed and t____ him her address(住址)．When he arrived at her house，she showed him her computer and the printer. David u____what the problem was right away．He told her,“From now on，print on white paper instead of blue!”

某市有6500名九年级学生参加数学毕业考试，为了了解这些学生毕业考试的数学成绩，从6500份数学答卷中随机抽取了300份进行统计分析，在这个问题中，样本容量是____．