单选题 圆x2+y2-2x+2y=0的周长是( ).
单选题 已知a为任意实数,则直线(a-1)x-y+2a+1=0一定经过点( ).
(2,3)
(-2,3)
(0,5)
(-2,0)
单选题 直线2x+y+2=0关于x轴对称的直线的方程是( ).
2x-y+2=0
2x+y+2=0
2x+y-2=0
x+2y+2=0
单选题 We must find a way to cut prices _____ reducing our profits too much.
without
despite
with
for
单选题 This problem is _____ his ability and I don’t think he can solve it.
To
in
beyond
under