引起肠道菌群失调的最主要病因是()。
A.正常菌群异位
B.宿主免疫力低下
C.滥用抗生素
D.黏膜表面损伤
E.长期大剂量应用糖皮质激素
参考答案:C
It is important that she _______ with Mr. Williams immediately. [ ]
A. speak
B. spoke
C. will speak
D. to speak
例举3种以上查询话费方式?