3characteristics of carbon that allow it to be considered the backbone

The carbon has 4 valence electrons ( can have four bonds ) that allow it to form bonds and takes 4 hydrogen atoms to become saturated. I cannot come up with a 3rd characteristic

really dont know just need some points

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.