Plants reacting to light is called phototropism. As plants need light to survive, by growing towards the direction of the light they give themselves the best chance of gettingâ¦ the most light.   Plants can tell the direction of the light because their surface has chemicals that react to light.
By On 11/29/15 at 12:30 PM. Refugees undergo the strictest background checks of any group of people entering the U.S. While some lawmakers have criticized the process for not being strict enough, it can sometimes take longer than two years, and Syrians go through an additional screening. Above, 5-year-old Syrian refugee Leen works on her homework at her new home in Sacramento, California, on November 16.
Turkey has taken in roughly 1.9 million refugees while Lebanon has accepted 1.1 million. The United States accepted 70,000 refugees from around the globe in 2013, the most recent year for which statistics are available. Roughly half of those were from two countries: Iraq and Burma.