Analysis of test questions: According to the historical facts after the Cultural Revolution, from 1976- 1978, individual leaders of the central government still insisted on two wrong views at that time: "We must support all decisions made by Chairman Mao and unswervingly carry out all instructions made by Chairman Mao." As a result, it was not on the right track at that time. In this case, the purpose of Deng Xiaoping's letter to the Central Committee in 1977 is to resist the "two whatevers". Therefore, the question should choose item C.

Comments: The background after the Cultural Revolution: The main leaders of the CPC Central Committee still adhere to the "Left" erroneous thinking. "Two whatevers" means "resolutely safeguarding all decisions made by Chairman Mao; We must always follow Chairman Mao's instructions. "

In order to emancipate the mind, the party's guiding ideology and all fronts urgently need to set things right, so a discussion on the standard of truth has been set off in the ideological field. Through discussion, we affirmed that "practice is the only criterion for testing truth" and re-established the Marxist ideological line of seeking truth from facts; (2) Breaking the shackles of cult of personality and dogmatism for a long time, people's thoughts have been greatly liberated; ③ To lay an ideological foundation for the Third Plenary Session of the Eleventh Central Committee and the new period of socialist modernization.