I think that it is important for children to play sports.
I have two reasons for this.
The first reason is that children need to exercise to be healthy.
If "they" 代名詞!play sports like baseball or basketball, they can "stay fit." 健康でいられる
The second reason is that when they play sports, they can challenge various things and make new friends through sports.
This is why I think that children should play sports.
※客観的に意見を述べた後、For example, で自分の経験を書いてもOK!
When I was on the baseball team, my teammates were very nice.
We are all friends still now.