What is the time that it takes for half of the chemical or toxin to be expelled from the body?

Mary is 14 year old her resting heart rate is 70 beats per minute. calculate 50% of mary's maximum heart rate to fine her target heart rate

Do not enter a place alone 1 public 2 seclude

Which organisms are consumers in an ecosystem? choose all answers that are correct. 1 grass 2 bacteria 3 lion 4 wolf