Little        _ that we were watching his every move, so he seemed to be going his own way in this

business:     [ ]

A. he realized            

B. he didn't realize    

C. didn't he realize          

D. did he realize

经济学家经常告诫投资者，不要把所有的鸡蛋都放在同一个篮子里。这一投资理念强调了投资的[ ]

A、流动性

B、灵活性

C、风险性

D、收益性