crazy bird是什么意思:英语语法词形转换

来源:百度文库 编辑:高校问答 时间:2024/05/01 17:14:37
They could not find any secrets。=They( )not ( )to find any secrets 。
为什么第一个空不用was?

第一个空填were,第二个空填able
be able to do 相当于can/could,表示有能力的意思。有多种时态变化。
were和are都是用于复数名词之后。they\we\you等都属于复数人称代词,所以要用were或是are

They were not able to find any secrets.

They were not able to find any secrets.be able to do意为有能力做某事

They were not able to find any secrets.
They的后面要接复数,怎么能接was呢?