影响我国西部环境人口容量的“短板”是
A．土地资源
B．淡水资源
C．热量资源
D．能源资源
答案：B
---- It is generally believed that teaching is __________it is a science.
A．an art much as
B．much as an art as
C．as an art much as
D．as much an art as
以下可作片剂助流剂的是
A．滑石粉
B．聚乙烯吡咯烷酮
C．淀粉
D．羧甲基淀粉钠
E．糊精
