Aseries of volcanoes make up the range.
a.
sierra nevada
b.
appalachian
c.
alaskan
d.
cascade

A series of volcanoes make up the Cascade Range. To be more specific, it includes the notable volcanoes known as the High Cascades. It also includes non-volcanic mountains such as the North Cascades. The Cascade Range is a major mountain range of western North America extending from southern British Columbia through Washington and Oregon to Northern California.

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].