Green frog tadpoles are best because they can be collected from ponds in autumn and watched during the school year as they grow legs, absorb their tails and change over from gill-breathing tadpoles to lung-breathing, flesh-eating adults.
(they; can be collected; from ponds in autumn) (they; watched; T:during the school year; T:as they grow legs)
they they
can be collected watched
from ponds in autumn
T:during the school year T:as they grow legs