1. [单选题]在正常人类染色体中，不会出现随体的是
A. 13
B. 14
C. 15
D. 20
E. 21
2. [单选题]骨髓纤维化确诊的主要手段是
A. 血象
B. 骨髓穿刺
C. 骨髓活检
D. 染色体核型分析
E. 细胞化学染色
3. [单选题] Which is the major regulator of proliferation and differentiation of megakaryocytes
A. erythropoietin
B. colony stimulating factors
C. .granulocyte colony-stimulating factor
D. interferon
E. thrombopoietin
