[单选题]对溃疡性结肠炎有诊断意义的病理改变是
A.干酪样肉芽肿
B.非干酪样肉芽肿
C.隐窝脓肿
D.肠系膜淋巴结炎性肿大
E.全壁性炎症

John F. Kennedy was the youngest American to be elected president of the United States. During the World War Ⅱ John F. Kennedy had an outstanding record in the Navy. After the war Kennedy worked briefly as a newspaperman, then entered polities. He was three times elected to the House of Representatives before becoming a senator from Massachusetts. In 1960 he was elected president in a very close race in which there were charges of irregularities.
Kennedy’ s term of office was marked by the achievements in appeals to idealism, a broad participation of people in politics, and improved civil rights. In international affairs, Kennedy saw the failure of the American - backed invasion of Cuban missile crisis which brought Russia and the United States to the brink of war.
The Kennedy family has experienced victories and tragedy. One of John Kennedy’ s sisters was mentally backward and an old brother was killed in the war. John Kennedy was assassinated
A. He was the youngest American elected president.
B. He was the richest American elected president.
C. He became president because he fought in the World War Ⅱ.
D. He became president because his family had suffered scandals.