They were surprised to see that they were b_____ by the river again.

问题描述:

They were surprised to see that they were b_____ by the river again.

他们吃惊的看着他们沿着河岸回来了
因为留着一空 所以我猜是 back吧

back 这是八年级的一个题.
他们惊奇的发现,他们又回到了河边.