Cannot see them or reach them. 중복동사는 생략합시다 (:
Since there????? Their
From dead stops.
Underdeveloped.
Take or to pray는 뭐시여.. 음?

The professor in the lecture talks about bats. Bats are unique because they are only mammals which can fly and they hang upside-down. The professor explains mainly two reasons why bats hanging upside-down. First, bats can hide from predators. During days, bats sleep in secluded spots such as the roof of the cave to hide from their predators. By hanging upside-down, the predators cannot see them. Second, hanging upside-down allows bats for ideal take-off. Since their wings are weak, they cannot fly from dead stops. Plus, bats’ hind legs are small and undeveloped; they cannot reach the proper take off speed. By hanging upside-down, they can just drop themselves and take off.