Gap junctions in the intercalated discs allow impulses to be spread across the heart more quickly. This is because gap junctions allow particles/signals to pass through, thus making cells with gap junctions more able to interact.
One more thing—you posted this in the physics section rather than biology.
1) It is because they produce a lot of pollution in the atmosphere
2) They are limited in number and can't be recycled
Hope this helps!
A (b) would be 42 (c) from x to Y mark me as brainlist thanks
Answer:
Balanced forces are equal and opposite forces that act on the same object. ... Action-reaction forces are equal and opposite forces that act on different objects, so they don't cancel out. In fact, they often result in motion.