A:c和f
B:c和d
C:a和e
D:a和d
唐朝的哪座城市,既是当时各民族交往中心,又是一座国际性的大都市( )
我国的四大牧区的简称分别是 ( )
已知函数f(x)=4x+3sinx,x∈(﹣1,1),如果f(1﹣a)+f(1﹣a2)<0成立,则实数a的取值范围为( )
—Can you finish _________these books before 10 o’clock
—Yes, I can
— Food safety has become a social focus now.
— That's why laws are made to crimes on food.