与十进制数89相等的数包括（）。
A.二进制数01011001
B.二进制数01011111
C.八进制数110
D.十六进制数59
参考答案：A, D
A dog ran in front of my mother’s car and she __________ stop very quickly.
A．ought to
B．had better
C．used to
D．had to
