One of the innumerable legends surrounding the construction of the Great Wall of China tells of a workman who estimated that he would need 99,999 bricks to construct a section of the wall now known as ...

Since 1978, China has planted more than 66 billion trees along its 2,800-mile-long northern border, and it wants to plant 34 billion more over the next 25 years to complete its "Great Green Wall." ...