下列气体中,既能用排水集气法收集,又能用向下排空气法收集的是
A、<img src="//wximg.233.com/attached/image/20130111/20130111153911261126.jpg" alt="" border="0" />B、<img src="//wximg.233.com/attached/image/20130111/20130111153951945194.jpg" alt="" border="0" />C、<img src="//wximg.233.com/attached/image/20130111/2013011115390381381.jpg" alt="" border="0" />D、<img src="//wximg.233.com/attached/image/20130111/2013011115390781781.jpg" alt="" border="0" />
物理化学综合