It was not until I received the text message that I knew___a serious disease he had been suffering from,and

began to worry about___he could pull through  this Christmas.[ ]

A.what; whether  

B.how ; if    

C. that;  that  

D .which ; how

研究心理现象的原则包括( )。

A．主观性

B．客观性

C．辩证发展

D．理论联系实际