CONCEPTS: cub, grass, hide

GEN: young lion cubs waiting for their mother while hiding in the long grass

CONCEPTS: come, look, track, train

GEN: A train is coming along near some unusual looking tracks.

CONCEPTS: organism, past, preserve, remain, trace

GEN: fossils preserved remains or traces of an organism that lived in the past .

CONCEPTS: chair, couch, plant, room

GEN:
A living room has a couch, a chair, and potted plants.