Why do we have ACE2 proteins?

It is the key to blocking infections

Explanation: I hope this is right :)

Base on your question the step of an aerobic exercise burns 11 calories per minute and a stretching exercise burns a 4 calories per minutes. Megan only has 40 minutes every morning to exercise and needs to burn 335 calories in a morning. The possible answer to your question is letter D. 25 min aerobics and 15 min stretching