某CuSO4溶液的质量分数是10%，该CuSO4溶液中Cu2+与水分子的个数比为[ ]
A．1：9
B．1：25
C．1：40
D．1：80
答案：D
The shop manager always says to his assistants, "We can never be ____customers.
A．so
B．too
C．that
D．more
软件测试策略包含哪些特征
