Some hormones are soluble in water, while others are not. Cortisol is a steroid hormone. Lutenizing hormone (LH) is a glycoprotein. Epinephrine is an amine (modified amino acid). Which of these hormones can cross the plasma membrane to interact with intracellular receptors

One of the characteristic feature of the phospholipid bi- layer is that like dissolve likes.Therefore,polar molecules and compounds pass though the hydrophllic heads,while non-polar lipid soluble substances pass through the hydrophobic tail,but can not diffuse across the head.

The plasma membrane is amphipathic.It  is made up of the hydrophilic heads  and hydrophobic tails

Cortisol is made of lipid.Therefore,it will diffuse easily across the bi layer of the plasma membrane though the tail,while LH and Epinephrine,will not diffuse across this hydrophobic barriers,since they are made up of polar molecules.

Explanation:

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.