James didn't come _____ the bell rang. [ ]
A. until
B. at
C. when
D. before
答案:A
胃大部切除术后切口皮下积液,经穿刺抽液后愈合,该愈合情况记录为()
A.Ⅰ/乙
B.Ⅱ/甲
C.Ⅲ/乙
D.Ⅱ/乙
E.Ⅱ/丙
免疫电泳常采用的琼脂糖浓度为()
A.0.8~1%
B.1~2%
C.2~3%
D.3~5%
E.5~10%