Tc细胞(CTL)杀伤肿瘤细胞的机制不包括A．分泌TNF等细胞因子间接杀伤瘤细胞 B

The mayor of Beijing says that all construction work for the Beijing Olympics___ now

A．has been completed

B．has completed

C．will have been completed

D．will have completed

用棉毡在管道上保温时，环向接缝应接合紧密，水平管道纵向接口应留在管子上部，应用镀锌铁丝或钢带扎紧，间距为( )。

A．200mm

B．400mm

C．500mm

D．100mm

—_______will your father come back?

—In a month.    [ ]

A. How long      

B. What time     

C. How often     

D. How soon

东风4型机车车轴上的从动齿轮与轮心的连接方式是（）。

A、过盈连接

B、键连接

C、特性连接

D、花键连接

抢救癫痫持续状态的患者，首选

A．水合氯醛灌肠
B．苯妥英钠静脉注射
C．安定静脉注射
D．氯丙嗪肌内注射
E．苯巴比妥钠肌内注射