宇宙飞船撞到小行星上可不是什么小事Opinion: Crashing a spacecraft into the asteroid is no boondoggle大约6600万年前的（66 million years ago）一天，一块大约6到10英里宽的巨石（a huge rock some 6 to 10 miles wide）...
2008年4月24日Southern Mexico and northern Central America experience a dry season that runs from roughly February through May each year. During that time, fires are common, both intentional agricultur...
