一个正方形周长是200米,边长是______米.
100÷4=20(米);
答:边长是20米.
故答案为:20.
制作口腔上皮细胞装片时,要将刮取的口腔上皮细胞涂抹到0.9%的生理盐水中,而不能涂抹到清水中,目的是
A.防止细菌在装片中繁殖
B.防止细胞吸水过多而胀破
C.迅速杀死细胞以便观察
D.利用生理盐水粘住细胞
The food my country is quite different that here.
A.in; like
B.to; from
C.from; to
D.in; from