Why is brain drain considered as a social problem?

Explanation:

The brain drain means that developing countries can struggle to develop because their best-skilled labour leaves the economy. Thus it becomes hard to break the cycle of losing the best workers. ... Migrants send money back to their country and they can return with improved skills and knowledge of business.

the first settlements began along the huang river because of the importance of the huang river in the beginning of china. it goes back to the story, “the tale of emperor yu”, which references the tale of the great flood, which was caused by the huang river and was believed to create and influence china’s making.

aliens are not real, the myth was created about 700 years ago because people found markings in the field of their crops. also, no there were no aliens on the moon.

hope this ! give brainliest!