The cultural revolution ended by the early 1970's in which three ways did it cause devastation in china

The Chinese Cultural Revolution was a profound political-ideological campaign carried out from 1966 in the People's Republic of China by the then leader of the Chinese Communist Party, Mao Zedong, whose aim was to neutralize the growing opposition to some of the less radical sectors of the party as a result of the failure of the Great Leap Forward economic plan (1958-1960), whose effects led to the death of millions of people due to the widespread famine known as the Chinese Great Famine.  

The campaign was accompanied by several episodes of violence, instigated mainly by the Red Guard, formed by groups of young people from the most diverse sectors (military, peasants, students, party elements, government, etc.) organized in the so-called "revolutionary committees" attacked those suspected of political disloyalty to the regime, to the figure of Mao and to Maoism, in order to consolidate (or restore) the power of the leader where it was needed. The targets of the Revolution were party members more aligned with the West or the Soviet Union, bureaucratic officials, and, above all, intellectual. As in the intellectuality were some of the potential enemies of the revolution, higher education was practically disabled in the country. It was in this period that the production and distribution of The Red Book, the collection of quotations of Mao that exalted his ideology and professed a form of cult to his personality, was leveraged.

Incidentally or intentionally, the movement eventually weakened Mao's opponents and represented a partisan depuration against the insinuating revisionism. The process was officially ended by Mao during the 9th Congress of the Communist Party of China in April 1969. However, experts say that it lasted, in fact, until Mao's death in 1976 and the rise to power of Deng Xiaoping, who gradually started the changes in the political and economic direction of the country.  

the answer is )multiethnic

a.   it resulted in widespread unemployment.