则y=f(x一2)的定义域是A,[-5,3]B,[-2,3]C,[-1,7]D,[1,5]x2-ax+5,x≤15,已知函数f(x)=a,x>1是R上的减函数,则实数a的取值范围是心专A,(0,3]B,(2,3]C [2,3]D,[2,3...

l.C【解析】细节理解题。根据第二段“From caringfor Jesse,he learns to understand better his own painand what brings meaning to one's life.”可知，强尼从...

4.C【解析】：函数)y=x-1)的定义域为[3]，是≤x1.综上，a≥1.故选A.△=a2-4(a-1)≥0 10.BC【解析】要使f(x)=√一x2+2x+3有意义，则有一x2+2x十3≥0，解得一1≤x≤3，...