If one bulb goes out then all the others won't light up because electricity will be cut off. It's a disadvantage because in a parallel circuit if one bulb burns out all the others will still be on because they won't be affected. I hope I've helped you ☺
A higher temperature, stiffer materials, and less dense materials increase the speed of sound.
Explanation:
This happens because the gas inside tend to expand because its temperature gets higher.
This is why the balloon that is put in a freezer for too long tend to gets smaller, because the gas temperature that is inside the balloon decreases.
(you can try it at home)
It is related to the temperature of the gas.