志贺菌感染病程在多长时间以上属慢性()。 ["2周","1个月","2个月","5个月","6个月"]
检测核酸浓度用可见光分光光度计,波长用()。 ["400nm","380nm","300nm","280nm","260nm"]
肺炎球菌菌体直径范围()。 ["0.2~1.0μm","0.5~1.0μm","0.5~1.25μm","0.5~2.0μm","0.5~2.2μm"]
在志贺菌中,其中一个血清群的菌落有光滑型和粗糙型两种,诊断血清中同时含有I相和Ⅱ相抗血清,这个血清群是()。 ["A群","B群","C群","D群","以上都不对"]
煮沸裂解法制备质粒时配制所用溶菌酶溶液的溶剂是()。 ["TE","TAE","TBE","TrisCl","冰醋酸"]
决定远期汇率的三个主要因素是()、买入和卖出的两种货币间的利率差和远期天数。