开放系统的标志是();()、可适宜性和可用性。
参考答案:可移植性、可操作性
下列各组离子一定能大量共存的是( )
A.在无色溶液中:NH4+、Fe2+、SO42-、CO32-
B.在含大量Ba2+的溶液中:NH4+、Na+、Cl-、OH-
C.在强碱溶液中:Na+、K+、Cl-、SO32-
D.在pH=1的溶液中:K+、Fe2+、Cl-、CH3COO-
—Where are you going to move?
—I'm going to move _____. [ ]
A. interesting somewhere
B. somewhere interesting
C. interesting anywhere
D. anywhere interesting