与肿瘤病人进行性消瘦有关的细胞因子是（）。
A.IFN
B.IL-1
C.IL-8
D.IL-2
E.TNF-α
参考答案：E
He was asked to _______ his class making a speech at the school opening ceremony.
A．represent
B．stand for
C．express
D．show
对于重载、低速的轴承，则应选用（）的润滑油。
A、粘度较低
B、粘度较高
C、粘度一般
D、无所谓
