So, I don't know the answer for b but I think I found the answer for a.
I sincerely hope this isn't wrong
Answer:
It increases endurance, builds muscle to maintain an optimal body fat composition, promotes cardiovascular health, strengthens the heart, and even improves your overall mood. Combined with weight training, running can help you maintain the perfect balance of mental stimulation and physical fitness.
Explanation:
B) ionic bond
(although in reality, every bond is fundamentally the sharing of a pair of electron. but due to unmutal electonegativity, the molecule becomes polar)
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Sorry, I'm am not going to entertain you!
But, have a great day!
#LearnWithBrainly
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Plus, here is a anime image that might make your day happy. . .