The bottlenose dolphin breathes air but can sleep in the ocean because it o ceases breathing while sleeping and remains underwater. o sleeps for only 30 minutes at a time, the maximum interval for which it can cease breathing. ofills its swim bladder with air to keep its blowhole above the surface of the water while it sleeps. moves to shallow water to sleep, so it does not need to swim to keep its blowhole above the surface of the water. o alternates which half of its brain is asleep and which half is awake.

The correct answer is the last option.

Explanation:

The bottlenose dolphins breathe air, however, at the same time can sleep in the ocean as it alternates with half of its brain as asleep and half as awake. This is due to the fact that half of the awake brain of a dolphin does not just keep the dolphin breathing, it also maintains the functioning of one eyeball so that it can see what is going in the surroundings, and at the same time, other eyeball remains shut.

the answer is c. it will give up it's valence electron to the other atom.

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

hope it ,

bioteacher101