Question

Lab work is fun but you must be careful. Listen carefully when your teacher reads and explains（解释）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 allowed in science lab.
Before the experiment	Read all instructions carefully before every experiment. Prepare all apparatuses (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 how to use the apparatuses or how to operate（操 作）, ask your teacher for help. ? Never smell or taste chemicals（化学药品）unless（除非）your teacher gives permissions.
After the experiment	Throw waste materials into proper waste baskets Wash all apparatuses after use and return them to the places where they were. Never smell or taste chemicals（化学药品）unless（除非）your teacher gives permissions.
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.You must know the LAB RULES ____________ the first lab lesson.

A.before B.since C.during D.after

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

3.If you are not: sure how to use the apparatuses, __________________.

A.read the rules carefully B.try them again and again

C.ask your teacher for help D.return all apparatuses to the places where they were

4.The underlined word "spill" means ___________________.

A.take care of B.run out of C.fall off D.pour out in drips

5.You should put the waste materials into the ____________.

A.packet B.paper bag C.bin D.waste baskets

6.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

Answer 1