________ you have ears? [ ]
A. Not
B. No
C. Don't
答案:C
7个排成一排,在下列情况下,各有多少种不同排法?
(1)甲排头;
(2)甲、乙、丙三人必须在一起;
(3)甲、乙、丙三人两两不相邻;
(4)甲不排头,乙不排当中.
(1)看日出 (2)下山(3)登山 (4)买门票(5)山上过夜正确选项为( )
A.2-5-4-3-1
B.4-3-5-1-2
C.2-1-4-5-3
D.2-3-4-1-5