单项选择题
A．increased slowly. B．decreased gradually. C．stayed steady. D．become unpredictable.
A．violated the traffic law. B．illegally attacked a boxer. C．attacked sb. after a traffic accident. D．failed to finish his contract.
A．they cover the whole story of the former US president. B．the assassin used to live in the former Soviet Union. C．they are the only official documents released about Kennedy. D．they solved the mystery surrounding Kennedy’s assassination.