What is the cell membrane composed of?

Membrane proteins are held in the bilayer mainly by

The most accepted Fluid Mosaic Model describes the cell membrane as a quasi-fluid structure where lipids and integral proteins are arranged in a mosaic pattern. In recent years,this model has been refined. Which of the following statements is incorrect regarding this model?

In the cell membrane,carbohydrates are attached to $...........$.

How are lipid molecules arranged in the cell membrane?

Monovalent ions (e.g.,$Na^+, K^+$) $A$ the membrane permeability,while divalent ions $B$ the same. Complete the given statement by filling in the appropriate option for ($A$ and $B$).