小船在河里用in/on the river,在太阳下是on/in the sun?在天空下是in the

问题描述:

小船在河里用in/on the river,在太阳下是on/in the sun?在天空下是in the
小船在河里用 in/on the river?
人/鱼在河里游用in/on?
在天空下是in the sky,那在天上怎么表达呢?
我要准确正确的答案,一定要准确正确.
不要给我一堆介词的用法.

a boat is on the water/river
swim in the river
in the sun在阳光下
in the sky在空中