单项选择题 投资风险中，非系统风险的特征是（）。 A. 不能被投资多样化所稀释 B. 不能消除而只能回避 C. 通过投资组合可以稀释 D. 对各投资者的影响相同

单项选择题 The reason why should we be positive employees can be as follows except_________?  A. The boss likes the people who always smile. B. The positive mood can be contagious. C. The postive mood can improve efficiency. D. The positive people look smart and powerful.

不定项选择 ​感冒的治疗原则，应以辛凉清解为主。‎