has been doing一般用来表示现在完成进行时。现在完成进行时的结构是“I/we/you/they have been doing sth.”、“he/she/it has been doing sth.”。表示从过去...
1、has been doing一般用来表示现在完成进行时。 2、现在完成进行时的结构是“I/we/you/they have been doing sth.”、“he/she/it has been doing sth.”。 3、...
as been doing一般用来表示现在完成进行时。现在完成进行时的结构是“I/we/you/they have been doing sth.”、“he/she/it has been doing sth.”。表示从过去某...
