Okay, let's find the odd words out in each list.
1) river, forest, lake, ocean, pond - The odd word out is forest because the rest of the words are water bodies.
2) big, little, large, small, busy - The odd word out is busy because the rest of the words describe sizes.
3) play, extend, east, enjoy, easy - The odd word out is east because the rest of the words are verbs (actions) or adjectives.
4) deep, beautiful, wide, narrow, high - The odd word out is beautiful because the rest of the words describe physical dimensions.
5) fresh, young, rich, station, powerful - The odd word out is station because the rest of the words describe qualities or states.