病人,女,26岁,近1个月来因不规则发热、乏力、体重减轻入院,经检查发现有房间隔缺损,并初步诊断合并亚急性细菌性心内膜炎,医嘱行血培养。采血量至少为()A.1~3mlB.4~6mlC.7~9mlD.10~15ml(正确答案)E.16~18ml