The biggest unsolved mysteries about Planet Earth

[ahlam1399]

http://static-global-s-msn-com.akamaized.net/img-resizer/tenant/amp/entityid/AAx8fqn.img?h=100&w=100&m=6&q=60&o=f&l=fFrom the water that covers most of it to the moon that orbits it, here are some bizarre things about our home planet that science still doesn't completely understand.

أكثر... (http://www.msn.com/en-ca/news/world/10-biggest-unsolved-mysteries-about-planet-earth/ss-AAxsv6c?li=AAggv0m&srcref=rss)