
A.a<-1
B.a≠-1
C.a≠1
D.a>1
[单选题]A.数目增加,间距不变B.数目增加,间距变小C.数目不变,间距变大D.数目减小,间距变大
[单选题]A.数目增加,间距不变B.数目增加,间距变小C.数目不变,间距变大D.数目减小,间距变大
[单选题]A.2x-y-1=0B.2x+y+1=0C.2x+y-3=0D.2x-y-+3=0
[单选题]A.1/πB.2/πC.3/πD.4/π
[单选题]A.0B.1C.-1D.2
[单选题]A.1B.1/2C.D.
[单选题]A.等于2B.等于0C.为∞D.不存在,但不为∞