A:细胞膜
B:细胞质
C:细胞核
D:细胞壁
画图:____
A____ B____
C____ D____.
①c= (w×1000×d)Mr
②m=V×d×( w100 )
③w%=(c×Mr).(1 000×d)%
④c= (1000×m)(V×Mr) .