(2011年浙江衢州,19题)如图所示的四个装置图及其使用方法的说明中,错误的一项是
答案:A
二氧化碳的密度大于空气,应用向上排空气法收集,应从a管通入。
Every possible means _____. However, nothing can _____ him dying of lung cancer. [ ]
A. has tried; stop
B. have tried; keep
C. has been tried; prevent
D. have been tried; stop
下列哪项不是小肠的结构与吸收功能相适应的特点?( )
A.小肠长5~6米
B.小肠内表面有许多皱襞
C.小肠绒毛中有毛细血管
D.小肠壁内有肠液