The answer is source B because it has a listed author who is an expert and it is the governments organization website which are more reliable that a .com website. Source A does not even list the author so you do not know who wrote it could be anyone.
Answer:
You can calculate your maximum heart rate by subtracting your age from 220. For example, if you're 45 years old, subtract 45 from 220 to get a maximum heart rate of 175. This is the average maximum number of times your heart should beat per minute during exercise. Find the best one that supports this and don't forget to give me a heart.
Answer:
Question in unclear..but I would say chemicals/hazards..? or wepons
Explanation:
