We often have classes in the lab（實(shí)驗(yàn)室）.There are many （1）

rules

rules

（rule） in the lab. Don't eat or drink in the lab. Don't （2）

bring

bring

（bring） food or drinks to the lab. There （3）

are

are

（be） three reasons. First， the bowls and cups are very easy to break and the food or drinks in the bowls or cups will be out. They will make the lab dirty. （4）

Second

Second

（two）， there are many chemicals（化學(xué)制品） in the lab. It isn't good（5）

for

for

us if we eat them. If you put the food （6）

or

or

drinks into your mouth in the lab， you may （7）

eat

eat

（eat） some chemicals. Of course， it is always a good idea （8）

to wash

to wash

（wash） your hands each time before you leave the lab. Third， food can attract（吸引） some mice（老鼠） and flies（蒼蠅）. So， if you want （9）

to drink

to drink

（drink） or eat something， do it （10）

outside

outside

the lab.