∵b=3a-1+1-3a+2,
∴3a-1≥01-3a≥0,
解得a=13,由此得b=2,
∴ab=23.
I wonder if your wife will go to the ball. If your wife _____,so _____mine. [ ]
A. does;will
B. will;does
C. will;would
D. does;do
若同一寄件人同时在同一邮局交寄同一收件人的数件邮件,要求撤回时,可只填写一份申请书,但应按件交纳手续费。()