安检部门在接控时,应查验()等有效文书。
A.《明传电报》
B.《明传简报》
C.《查控对象通知单》
D.《民航内部通报》
参考答案:C
All the staff in our company are considering to the city centre for the fashion show.[ ]
A. to go
B. going
C. to have gone
D. having gone
已知函数f(x)=(ax2-2x+1)•e-x(a∈R,e为自然对数的底数).
(I) 当a=1时,求函数f(x)的极值;
(Ⅱ) 若函数f(x)在[-1,1]上单调递减,求a的取值范围.