保兑信用证是指该信用证在一定时间内利用规定金额后，能够重新恢复信用证原金额而再被利用，直至达到规定次数或规定的总金额为止。
参考答案：错
Urban crowdedness would be greatly relieved if fares ________ on public transport were more reasonable．
A．offered
B．charged
C．paid
D．spent
成矿阶段
