Are the following sentences grammatically correct?  If not, please find out the mistakes.

1. In poor families, teenagers must do the housework while their parents work.
2. His friend came from a poor part of town.
3. Some communities in Somalia in Africa are extremely poor.

Are the following sentences grammatically correct?  If not, please find out the mistakes.

1. I would like to suggest that the popularity of smartphones has brought a negative impact to family relationships.
2. Do you think that playing video games brings about a positive or negative effect on our brains?
3. Playing sport creates a positive impact on young people.

Are the following sentences grammatically correct?  If not, please find out the mistakes.

1. Nowadays different media plays different roles in communicating information.
2. Many new medias have revolutionised the way we get our information.
3. In this essay I will explain the differences between new medias.