下列哪些中药材断面可见同心环（）
A.牛膝
B.川牛膝
C.商陆
D.鸡血藤
E.何首乌
参考答案：A, B, C
--- I want to know if she ______ in my birthday party tonight.
--- I believe if she ______ her homework, she will join us.
A．will join; will finish
B．will join; finishes
C．joins; finishes
D．joins; will finish
血液发出后，受血者和供血者的血样保存于2～6℃冰箱中至少应保存多少天（）
A.4天
B.5天
C.6天
D.7天
