¿Por qué hay un cambio climático?

Amath expression is a collection of one or more terms, which are separated by the signs ( + , - , x , / ).example :   8+b8+b  or  a−3a−3in algebra, an equation is a mathematical statement with two expressions where, each expression is separated by an equal (=) sign. variables can be present on both the sides of the equality (=) sign and we use letters to denote such variables.example 1:   x=4+2x=4+2  , [here, we can observe that the variable is present only on one side of the equation].example 2:   2x+3=x+42x+3=x+4  , [here, we can observe that the variables are present on both side of the equation].

Mexico has a host of environmental problems, including significant chemicalpollution  from factory discharges and waste dumping, but the main threat to itsbiodiversity  probably stems from  deforestation  and other natural habitat losses. forest habitat is lost for a number of reasons

Ithink its b but i'm not sure.