单项选择题

On November 22, 1963, President Kennedy, John Fitzgerald and his wife Mrs. Kennedy were in Dallas, Texas, trying to win support in the state. On his way to a luncheon in downtown Dallas, Kennedy and his wife sat in an open convertible at the head of a motorcade(车队). Vice President Lyndon Johnson was in two cars behind the president, and Texas Governor John Connally and his wife were sitting with the Kennedys. The large crowds were enthusiastic.
As the motorcade approached an underpass(地下通道), two shots were fired rapidly. One bullet passed through the president’s neck and struck Governor Connally in the back. The other bullet struck the president in the head. Kennedy fell forward, and his car sped to Parkland Hospital. At 1:00 PM, he was pronounced dead. He had never regained consciousness.
So, Kennedy was assassinated before he completed his third year as president. His achievements, both foreign and domestic, were therefore limited. Nevertheless, his influence was worldwide, and his handling of the Cuban missile crisis may have prevented war. Young people especially admired him, and perhaps no other president was so popular. He brought to the presidency an awareness of the cultural and historical traditions of the United States and an appreciation of intellectual excellence. Because Kennedy eloquently expressed the values of 20th-century America, his presidency had an importance beyond its political achievements.
Less than two hours after the shooting, Lyndon Johnson was sworn in as the 36th president of the United States.

His presidency had an importance beyond its political achievements because（）.

点击查看答案&解析