半数致死剂量或浓度LD50/LC5O
参考答案:
指口服/注射等方式制毒,在一定时间内致毒而使动物死亡一般的剂量
单词拼写(共5小题,计5分)阅读下列各句,根据所给首字母在各题横线上写出所缺单词,使各句语义完整和正确。
小题1:Mr. White is a teacher. He works in a middle s________.
小题2:I g________ up at haft past six every morning.
小题3:In Changsha it's very hot in summer and very c________ in winter.
小题4:I could look a________ myself well when I was ten.
小题5:Please keep your eyes closed. Don't o________ them until I say "OK".
男孩,6岁。低热5天,两下肢及臀部有出血性皮疹,高出皮面,伴腹痛,便血一次,可能的诊断是()
A.血小板减少性紫癜
B.流行性脑脊髓膜炎
C.过敏性紫癜
D.坏死性肠炎
E.消化性溃疡