You'd better go there by train.The train ticket is________the airplane ticket. [      ]

A. as cheap three times as  

B. as three times cheap as

C. three times cheaper than  

D. cheaper three times than

一粘连性肠梗阻的患者，出现持续性腹痛、阵发性加剧。体检：腹部压痛、反跳痛、无肌紧张，肠鸣音10～12次／分，未闻及气过水声。宜采取何种措施（）

A.密切观察腹部体征变化

B.腹部X线检查

C.解痉抗感染治疗

D.胃肠减压

E.积极剖腹探查