A:有无以核膜为界限的细胞核
B:有无多种细胞器
C:有无染色体
D:有无核糖体
Sorry, I can't ________ you. Can you ________ it again?
图是制作临时装片的几个步骤,正确的操作顺序是( )
①﹣|﹣ 12 |=____
②﹣(﹣6)=____
③(﹣1)99=____.