比如，可以通过许可证的发放将船闸通行限定在指定时间内，而且许可证也可以在拖船船长之间进行交易。

For example, permits could be issued to travel through locks at specified times, and those permits could be traded among towboat captains.

youdao

比如，可以通过许可证的发放将船闸通行限定在指定时间内，而且许可证也可以在拖船船长之间进行交易。

For example, permits could be issued to travel through locks at specified times, and those permits could be traded among towboat captains.

youdao