1．Long before the arrival of Europeans，on the Canadian prairie，people lived in a harmonious relationship with their natural surroundings. (完形填空第一段)
在欧洲人到来之前的很长时间，在加拿大大草原上，人类和自然环境和谐相处。
(1)She said that she had known your name long before.
她说她很久以前就知道你的名字。
(2)I finished my work long before I return home.
我回家之前早已把工作干完了。
