社会心理因素的特点不包括
A．概念非常复杂
B．各因素之间存在广泛的交互作用
C．具有不稳定性
D．具有较强的主观性
E．测量的信度和效度较高
参考答案：E
The number of people invited ____ fifty, but a number of them ____ absent for different reasons.[ ]
A. were, was
B. was, was
C. was, were
D. were, were
简述“杯酒释兵权”。
