The buyer has the right to cancel the contract unilaterally if the seller fails to ship the goods within the L/C validity.
如果卖方不能在信用证有效期内交货的话,买方有权单方面取消合同。
He did a lot of research and travelled around the USA looking for information about his ancestors.
他做了大量的研究,在美国跑了许多地方,了解有关祖先的情况。