患者女，50岁。反复脓血便半年，每天3～5次，在当地曾按痢疾治疗无明显效果。近1个月出现腹胀，伴阵发性腹痛。查体：消瘦，腹稍胀，软，下腹轻压痛，右下腹可扪及一肿块，质较硬，尚可活动。

首选的辅助检查（）

A.大便细菌培养

B.CT

C.钡餐检查

D.纤维结肠镜检查

E.MRI

The children kept their eyes _____ when they _____ Liu Qian's tricks. [ ]

A. opening; looked

B. open; were watching

C. opening; watched

D. open; were looking