用光学显微镜观察发生质壁分离现象的洋葱表皮细胞,不能检视到染色体的原因是[ ]
A.没有用龙胆紫染色
B.试剂破坏了染色体结构
C.无染色体形成
D.显微镜倍率不够
答案:C
Turner牙是指()
A.先天性梅毒的半月形切牙
B.氟斑牙
C.牙中牙
D.因乳牙根尖周严重感染致其继承恒牙牙釉质发育不全
E.多生牙
People may have different opinions about Kaven, but I admire her.________she is a great musician. [ ]
A. After all
B. As a result
C. In other words
D. As usual