市场营销环境分为()和()两大类。
参考答案:宏观环境;微观环境
下列离子能大量共存而且溶液为无色透明的是( )
A.NH4+、Al3+、SO42-、NO3-
B.Cu2+、Na+、NO3-、CO32-
C.Na+、K+、OH-、Mg2+
D.H+、K+、HCO3-、CO32-
It's difficult to _____ a conversation with someone who only says "Yes" and "No".[ ]
A. call up
B. set out
C. keep up
D. bring out