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.
1 The average processing time for refugee applications is about 12 to 18 months, but Syrian applications can take longer.  U.S. government data shows that just under 2,200 Syrian refugees have been admitted into the U.S. since the civil war broke out.