As , when the earthworms crawl inside the soil , it gets holes by which air can enter the soil and the growth of plant is fast.
Answer: The respiratory system, the circulatory system, and the muscular system
Hope this helps :)
This can be because of their genetics. The siblings may not have inherited their parents looks, but maybe they inherited their grandparents looks, or even their aunts looks. This is all due to genetics. It's sort of the same thing, when two caucasian parents have an african-american child. That would be because somewhere along the family tree someone was african-american.
Anyways, I hope this helps!