组织培养中进行细胞纯化时可以采用下哪一种实验技术（）

A.细胞克隆技术

B.细胞筛选技术

C.细胞蚀斑技术

D.有限稀释法

E.无限稀释法

—You'd better () work too hard like this.
—I see. You mean () too hard makes one tired and ill.

A．not; work

B．don't; working

C．don't; to work

D．not; working