Pioneers who crossed the western mountains in the mid-1800s were threatened by exposure to too much sun. apache and comanche attacks. snow and cold temperatures. slow travel across sand.

The correct answer is C) snow and cold temperatures.

The Pioneers who crossed the Western mountains in mid-1800s were threatened by snow and cold temperatures.

The Pioneers faced so many dangers when they crossed the Western mountains in the 1800s. The heavy snow, the extremely cold weather, and the wildlife were among the threatens during their expeditions. Diseases stroke many of the Pioneers who died in the intent to cross the mountains.  

the great wall of china worked as a defense for the feudal states of the zhou dynasty to the north. during the warring states period more walls were put up to defend the borders of the different kingdoms. it was semi successful because despite the wall, the mongols eventually conquered china also the great wall provided protection to the economic development and cultural progress, safeguarded the trading routes such as the silk road, and secured transmission of information and transportation. @jayxboof

first industrial revolution - the first wave of the industrial revolution lasted from the late 1700s to the mid-1800s. it industrialized the manufacture of textiles and began the move of production from homes to factories. steam power and the cotton gin played an important role in this period.