A.
x=int(input("请输入一个数:")) if x<0 or x>30: print(-5) elif 0<=x<5: print(x) elif 5<=x<10: print(3*x-5) elif 10<=x<20: print(0.5*2+1)
B.
x=int(input("请输入一个数:")) if x<0 or x>=30: print(5) elif 0<=x<5: print(x) elif 5<=x<10: print(3*x-5) elif 10<=x<20: print(0.5*2+1)
C.
x=int(input("请输入一个数:")) if x<0 or x>=30: print(-5) elif 0<=x<5: print(x) elif 5<=x<10: print(3*x-5) elif 10<=x<20: print(0.5*2+1)
D.
x=int(input("请输入一个数:")) if x<0 and x>=30: print(-5) elif 0<=x<5: print(x) elif 5<=x<10: print(3*x-5) elif 10<=x<20: print(0.5*2+1)