all men need air,完形填空
All men need air.We __1__in air from outside our __2__every breath。When you put your face under water you cannot keep it __3__long.
Aswimmer cannot swim under water very long.He needs__4__.A good swimmer may swim with his face in the water if he keeps turning up his __5__to take a breath through his mouth.If he goes down under the water ,he__6---come up for air every twenty or thirty__7__.
He does not take in air through his nose under the water __8__water could get in through his nose with the air and go to his lungs.__9__water in his lungs,a man __10__go on living.