The new Nokia Here Maps have an option that enables you to download maps to your iPhone or iPad via Wi-Fi, so there won't be any data connection needed the next time you will be using the app.
Another great TEDtalk about genetically engineering male mosquitoes to make them sterile, and releasing the insects into the wild, to cut down on disease-carrying species.
The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders.
