Aunion that represents members of a specific occupation, such as truck drivers, is known as

Labor unions represent workers in particular industries, trades or sectors. They organize their members to negotiate improved wages, benefits and working conditions. Although union membership in the United States peaked in the mid-20th century and has declined since then, various types of labor unions remain an influential force in American business and politics.

  b.

there are isolated pockets of farming, generally around rivers and oases, which are used for irrigation.

f 5 , h