对于原发性骨髓纤维化,下列哪项是错误的()
A.骨髓穿刺干抽
B.均有显著脾大
C.按起病急缓可分为慢性型和急性型
D.外周血中有幼粒、幼红细胞
E.NAP活力增高
参考答案:B
Susan's father was pretty anxious because he ______ his notebook on the bus. [ ]
A. dropped
B. fell
C. broke
D. showed
细胞内产生和贮存能量的场所是:()
A.内质网
B.线粒体
C.溶酶体
D.染色体