Sugars are large, hydrophilic molecules that are important energy sources for cells. how can they enter cells from an environment with a very high concentration of sugar?

The correct answer is by facilitated diffusion.  

The procedure of continuous passive transport of ions or molecules through a semi-permeable membrane with the help of particular transmembrane integral proteins is known as facilitated or passive-mediated transport or facilitated diffusion.  

It is a modification of osmosis incorporating a proteinaceous channel via which an extracellular solute can enter a cell in the absence of energy.  

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

emerging idea only occurs as a raw idea that could appear out of nowhere. meanwhile, to reach scientific consensus , that idea must be structured and tested over and over again through various experiments. the scientific consensus transforms the raw idea into idea that is more reliable through the process of scientific elimination.