Can you tell me ________ the problem of stress?

A．what I should deal with

B．how I should do with

C．what to deal with

D．how to deal with

肿瘤组织分化程度越低表示（）。

A.肿瘤恶性程度越高

B.肿瘤与原来的组织相似

C.肿瘤预后好

D.肿瘤转移越晚

E.肿瘤对放化疗不敏感