患者行结肠镜检查并取病理，其正确的病理组织描述为

A．黏膜固有层可见大量嗜酸细胞聚集

B．黏膜固有层可见大量淋巴细胞聚集

C．黏膜固有层发现非干酪性坏死性肉芽肿

D．黏膜固有层发现干酪性坏死性肉芽肿

E．黏膜固有层发现大量巨噬细胞

She had just finished her homework ________ her mother asked her to practise playing the piano

yesterday.[ ]

A. when  

B. while

C. after  

D. since