安监总局第33号令文件名称是什么？
参考答案：《煤矿领导带班下井及安全监督检查规定》
Jim likes to ___________ his dog at home. [ ]
A. play at
B. play with
C. look at
D. look for
测定NK细胞杀伤活性( )
A．Western Bloting B．细胞毒实验 C．溶血空斑实验D．E花环实验 E．PHA淋巴细胞转化实验
