Question

what happened when the czechs tried to implement liberal reforms in 1968?
the communist government was forced to step down.
slovakia protested and blocked the proposed changes.
the ussr and other warsaw pact nations invaded
czechoslovakian residents gained new civil liberties.

Explanation:

In 1968, when the Czechs tried to implement liberal reforms (Prague Spring), the USSR and other Warsaw Pact nations invaded to stop the reforms. The communist government was not forced to step down (it was pressured but remained in a subservient position to the USSR after the invasion). Slovakia did not block the changes in the way described - the main opposition was from the Soviet - led bloc. And the residents did not gain new civil liberties as the invasion reversed the liberalizing trends.

Answer:

The USSR and other Warsaw pact nations invaded.