What sport is played during two periods of 45 minutes each, and involves a system of fouls using red and yellow cards? a. soccer b. volleyball c. lacrosse d. tennis

Soccer because when the referee is suspicious of something that stop the game and decides if he/she is going to get a red card or yellow card. Also, after 45 minutes, the have halftime and go back another 45 minutes, which equals 90 minutes total for the whole game.

Its oxygen. they put it into a tube into your nose.