—___do you water the flowers?  

—Twice a day. [ ]

A. How long          

B. How ma ny times        

C. How often      

D. How soon

治疗自身免疫性肝炎的首选药物是（）

A.糖皮质激素

B.硫唑嘌呤

C.环孢素

D.熊去氧胆酸

E.甘草酸苷