【单选题】I am sure David will be able to find the library because he has a pretty good ______ of direction.
【单选题】I am_____sure that I have told you that before.
【单选题】《卡文迪什实验室·现代科学革命的圣地》的作者是谁?
【单选题】根据《GB/T 6682-2008 分析实验室用水规格和试验方法》可知,分析实验室用水共分三个级别:一级水、二级水和三级水,以下几项中不用于纯水检验的技术指标是:( )
【单选题】--- Whose Chinese vase is it? --- I have no idea, but I’m pretty sure it _______ the old lady.