From 1948 to 1955 he was a political science professor at Columbia University, and then a history professor from 1955 to 1969.
From 1948 to 1955 he was a political science professor at Columbia University, and then a history professor from 1955 to 1969.
From 1948 to 1955 he was a political science professor at Columbia University, and then a history professor from 1955 to 1969.
让句子变得更简单: From 1948 to 1955 he was a political science professor at Columbia University, and then a history professor from 1955 to 1969. 输出: