22.We often have classes in the lab(實驗室).There are many (1)
(rule) in the lab. Don't eat or drink in the lab. Don't (2)
(bring) food or drinks to the lab. There (3)
(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)
(two), there are many chemicals(化學制品) in the lab. It isn't good(5)
us if we eat them. If you put the food (6)
drinks into your mouth in the lab, you may (7)
(eat) some chemicals. Of course, it is always a good idea (8)
(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)