关于单克隆抗体的描述下列哪项是错误的（）

A.生物活性专一

B.纯度高

C.特异性高

D.可识别多个表位

E.可用于诊断和治疗

The students in the international school are encouraged to voice whatever opinions they have and

question authority, which helps to develop their______ thinking. [      ]

A. cautious  

B. casual

C. careful  

D. critical