For centuries the Atlantic Ocean kept the Americans from ____ (discover) by the people of Europe.
问题描述：
For centuries the Atlantic Ocean kept the Americans from ____ (discover) by the people of Europe.
答案being discovered,被动语态?为何前面要用being,而不是were discovered?而且be为何要变成进行时?
答
这句话的意思是几个世纪以来大西洋阻止了美国被欧洲人发现.from是介词所以后面要用ing形式,而美国是被发现的,所以要用被动形式.和在一起就是being加被动（v-ed）,being discovered