What is the least amount of time you should stay in your heart rate ?

a. 20 minutes
b. 10 minutes
c. 5 minutes
d. 2 hours

In strenuous physical activities it is recommended to warm up and cool down ? true or false ?

Mucous membranes.. a. cover or line external surface of body. b. line internal body surfaces that are in contact with the environment. c. produce antibodies to combat infection. d. secrete sweat, which has antibacterial enzymes.

Ireally need to know this answer asap