An invasive creeping weed native to the Mediterranean region, Cirsium arvense has been present in Yellowstone National Park at least since the 19th century. Because of its extensive root system, the plant defies attempts to (i)____________ it by normal methods, and consequently, park officials have (ii)____________ efforts to do so. Warming temperatures have also (iii)____________ the thistle's fortunes. A. control B. largely abandoned C. helped D. study E. recently reinitiated F. undermined G. nourish H. increasingly promoted I. illuminated