----What are you busy doing these days?

----I______ study for the coming exam.

A．hardly

B．mainly

C．nearly

D．exactly

患者女，37岁，下唇黏膜糜烂半年，检查见下唇中部1cm×0.8cm病变区，黏膜糜烂、充血、结痂，可见灰白色放射状条纹。活检镜下可见上皮变薄，上皮钉突呈锯齿状，基底细胞水肿液化，结缔组织内可见大量淋巴细胞围绕血管浸润，血管不规则扩张，管壁不完整。应诊断为

A．白斑

B．慢性盘状红斑狼疮

C．扁平苔藓

D．口腔黏膜下纤维化

E．上皮异常增生