- 已知集合 \(M=\left\{-2,-1,0,1,2\right\}\) ，\(N=\left\{x\left|x^{2}-x-6\geq0\right.\right\},\)则 \(M\cap N=\)
A.\(\{-2,-1,0,1\}\)
B.\(\{0,1,2\}\)
C.\(\{-2\}\)
D. 2
2.已知 \(z=\frac{1-i}{2+2i}\)，则\(z-\overline{z}=\)
A. -i
B. i
C. 0
D. 1
3.己知向量 \(\vec{a}=(1,1),\vec{b}=(1,-1)\)，若 \(\left(\vec{a}+\lambda\vec{b}\right)\perp\left(\vec{a}+\mu\vec{b}\right)\) 则
A.\(\lambda+\mu=1\)
B.\(\lambda+\mu=-1\)
C.\(\lambda\mu=1\)
D.\(\lambda\mu=-1\)
4.设函数 \(f(x)=2^{x(x-a)}\) 在区间(0,1)上单调递减，则a的取值范围是
A.\((-\infty,-2]\)
B. [-2,0)
C.(0,2]
D.\([2,+)\)
5.设椭圆 \(C_1:{\frac{x^2}{a^2}}+y^2=1(a>1),C_2:{\frac{x^2}{4}}+y^2=1\) 的离心率分别为\(e_1\),\(e_2\),，若 \(e_2=\sqrt{3}e_1,\) 则a=
A.\(\frac{2\sqrt{3}}{3}\)
B.\(\sqrt{2}\)
C. \(\sqrt{3}\)
D. \(\sqrt{6}\)