What is meant by the following statement.

the cell membrane is semipermeable?

Cell membrane ( also called plasma membrane, made up of two layers of phospholipids) is a membrane surrounding the cytoplasm of all cells and separates the internal environment of cell from its external environment.

It is a semipermeable membrane, which means that it allows the entry and exit of only specific molecules ( such as small uncharged molecules, small polar molecules like Oxygen and Carbon-dioxide, small uncharged polar molecules like water). Also, it does not allow the toxic substances to enter the cell and at the same time the useful substances to leave the cell.

By doing so, it acts like a protective barrier for the cell.

answer; hypnagogic sensations)

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.