去年栽树b棵，今年栽树是去年的m倍，今年栽树______棵．
b×m=bm（棵）；
答：今年栽树bm棵；
故答案为：bm．
I was out of town at the time，so I don’t know exactly how it ________.
A．was happening
B．happened
C．happens
D．has happened
无符号二进制整数00110011转换成十进制整数是( )。
A．48
B．49
C．51
D．53
