1. (2017·赤峰) 根据表格内容，选择最佳答案。

    Lab work is fun but you must be careful. Listen carefully when your teacher reads and explains the rules before your first lab lesson.

LAB RULES
Throughout the lessons	* Do not enter the science lab without the teacher's permission(允许). * No food or drinks are to be allowed in the science lab.
Before the Experiment	* Read all instructions carefully before every experiment(实验). * Prepare all apparatus(仪器)and put them in right places so that you will not knock them over while doing the experiment.
During the Experiment	* If you are unsure of how to use any apparatus or how to operate, ask your teacher for help. * Never smell or taste chemicals unless your teacher gives permission.
After the Experiment	* Wash all apparatus after use and return them to the places where they were. * Throw waste materials into proper waste baskets.
First Aid	* Report all accidents to your teacher immediately. * If you spill any chemicals onto your body or clothing, wash with plenty of water and report to your teacher.

1. （1） You must know the LAB RULES ______ the first lab lessons.

   A . before B . since C . during D . after
3. （2） It is necessary for you to ______ before every experiment.

   A . read all instructions carefully B . take enough food and drinks C . smell chemicals immediately D . talk with your classmates.
5. （3） If you are not sure of how to use any apparatus, ______.

   A . read the rules carefully B . try them again and again C . ask your teacher for help D . return all apparatus to the places where they were
7. （4） The underlined word “spill” means ______.

   A . 照射 B . 伤害 C . 摔下 D . 溅出
9. （5） When you are in the science lab, you mustn't ______.

   A . be careful in order to prevent injury B . listen carefully when your teacher explains the rules C . taste chemicals without the teacher's permission D . throw waste materials into proper waste baskets