A:didn’t; would it
B:doesn’t; it will
C:didn’t; it would
D:doesn’t; will it
People are starting to use energy from the sun, wind and water because they cost very ________ and will never ________.
甲、乙两地的实际距离是210千米,在比例尺是1:3000000的地图上,甲、乙两地的距离是____厘米.
已知,函数y=(1-3k)x+2k-1,试回答: