6人站成一排照相,其中甲,乙,丙三人要站在一起,并且乙,丙要站在甲的两边,则不同的排法种数共有______种.
不同的排法种数有A22A44=48种
股答案为48
Yi Zhongtian’s simple and interesting explanation of history has _________ lots of TV viewers.
A.caused
B.attacked
C.tested
D.attracted
PTCD常用的穿刺部位是()
A.右腋前线8~10肋间
B.右腋中线10~11肋间
C.右腋后线9~10肋间
D.右腋中线8~10肋间
E.右腋后线10~11肋间