车削批量较大的多线蜗杆时,半精车后表面粗糙度Ra值应在()范围内。
A.3.2~2.5um
B.6.2~3.2um
C.12.5~6.3um
D.25~12.5um
参考答案:C
Tom, who is always shy in public, has made some friends at school, ______ has pleased his parents.
A.who
B.where
C.that
D.which
男性,43岁。既往体质差,常有发热及服多种药物史,近因尿色旱红茶样就诊。化验:RBC2.0×1012/L,Hb58g/L,门细胞及血小板_F常,网织红细胞0.12(12%),尿隐血阳性,血清游离血红蛋白600mg/L,诊断为血管内溶血。除下列哪个疾病外,余均可引起血管内溶血()
A.葡萄糖-6-磷酸脱氢酶(G-6-PD.缺乏症
B.疟疾
C.阵发性睡眠性血红蛋白尿
D.自身免疫性溶血性贫血
E.阵发性冷性血红蛋白尿