I will be surprised if you can get Calvin, who is a close-fisted man, ____these donation draw tickets

from you. [ ]

A. buy

B. buying

C. buys

D. to buy

人成熟红细胞无细胞核.精子细胞中细胞质很少，这些细胞的寿命都很短，这一事实体现了（）

A.环境影响细胞寿命

B.细胞中遗传物质不同寿命不同

C.细胞核的功能比细胞质重要

D.细胞是一个有机的统一整体