China ______ a lot of people moving to urban areas in the last 20 years. However, many migrants  left their families behind.

A．saw

B．sees

C．has seen

D．had seen

患儿，10个月。腹泻3天，鼻塞流涕，每日大便10余次，呈稀水样，臭味不甚，尿黄。查体：体温38℃，皮肤弹性尚好，前囟平，哭时有泪。听诊心肺正常，肠鸣音亢进，舌苔薄白，指纹红，达于风关。大便镜检无异常。应首先考虑的是（）。

A.细菌性肠炎风寒证

B.细菌性肠炎湿热证

C.病毒性肠炎风寒证

D.病毒性肠炎湿热证

E.霉菌性肠炎风寒证