The sun is the same shape in the sky every day, but the moon's shape changes throughout the month. What could be an explanation for the
moon's changing shape?

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

he uptake of drugs from the intestine is often strongly influenced by diffusion. for example, consider a water-insoluble steroid for treating inflammation that is solubilized in aggregates of detergent molecules, called micelles. these micelles, aggregates of 80 soap molecules, have a molecular weight of 24,000, a diameter of 2.6 nm, and a charge of -27. the positively charge ions (counterions) in this system are na".