船是用in the river 还是on the river

船是用in the river 还是on the river on the river?in the river? 是The ducks are swimming on the river 还是in the river?是There a 是there is a boat in the river还是there is a boat on the river [英语]在河上钓鱼的人是on the river还是in the river? in the river与 on the river的区别 in the river和on the river有什么区别 on a river,on the river,in the river的区别 on the river the river huangpu 还是the huangpu river? 英语:“一艘小船在河里”,是用on the river还是in the river?(A boat is _____ t in the river意思