英语完形填空He doesn't take in air through his nose under the wate

英语完形填空
He doesn't 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.
8) A)because B)if C)when D)where
9)A)In B)With C)By D)Under
10) A)can't B)mustn't C)needn't D) may not