Last night, my daughter asked me:"Mama, why is sea water salty, but river and lake water isn't salty?"
I was stuck because I never thought this question in the past 33 years and she is just three year's old. So I said:"That's a good question. Let's check the answer together."
I was stuck because I never thought this question in the past 33 years and she is just three year's old. So I said:"That's a good question. Let's check the answer together."
If you, my friend, don't know the answer like me, please watch the videos below:
http://www.youtube.com/watch?v=-8ru4r7xPkE
http://www.youtube.com/watch?v=Lwzoh38alGE
http://www.youtube.com/watch?v=-8ru4r7xPkE
http://www.youtube.com/watch?v=Lwzoh38alGE
