I think _______ very important for students to study by themselves in the school or at home.[ ]

A. it

B. this

C. that

急性胰腺炎治疗中对糖皮质激素应用所采取的原则是（）

A.为减轻水肿、缓解疼痛可用

B.为对抗应激状态可适量应用

C.仅用于出血坏死型伴休克或成人呼吸窘迫综合征者

D.为减少局部并发症发生可选用

E.确诊为出血坏死型者均需酌情应用