题目内容：

是The ducks are swimming on the river 还是in the river?是There are some boats on the river还是in the river

优质解答

The ducks are swimming in the river
There are some boats on the river

追问：

是ducks的还是boats的？

追答：

The ducks are swimming【 in】 the river
There are some boats 【on】 the river