若(x2-1ax)9(a∈R)展开式中x9的系数为-212,则常数a=_____ 发布时间:2017-05-16 12:22 │ 来源:www.tikuol.com 题型:填空题 问题: 若(x2-1ax)9 (a∈R)展开式中x9的系数为-212,则常数a=______.
题型:填空题 -Why are you in such a hurry? -I was told that my mother had been sent to the hospital. I have to leave ________.[ ]A.before long B.right nowC.from now on D.all the time 查看答案
题型:填空题 男,17岁,高热5天伴纳差3天就诊,当天查血压 105/75mmHg,左趾甲沟部破溃流脓,左侧小腿肿胀,皮肤发红不明显,白细胞计数20×109/L,中性粒细胞为0.85。如未经血细菌培养证实以上判断,根据经验应首选的抗菌药物是A.丁胺卡那霉素B.羧苄西林C.红霉素D.万古霉素E.甲硝唑 查看答案