The girl was very sad, and she seemed _____ the fact that she didn’t pass the exam.[ ]

A. telling                            

B. having told

C. to be told                    

D. to have been told  

与Tc细胞活化、增殖、分化有直接关系的是( )

A．协同刺激分子受体
B．MHC Ⅱ类分子
C．EPO
D．TNF
E．GM-CSF