they have been collecting stamps for 10 years在 collecting stamps下画线了对画线部分进行提问( ) have they ( )( )for 10 years?

分类: 作业答案 • 2022-04-15 09:20:07

问题描述：

they have been collecting stamps for 10 years
在 collecting stamps下画线了对画线部分进行提问
( ) have they ( )( )for 10 years?

答

What have they been doing for 10 years?

they have been collecting stamps for 10 years在 collecting stamps下画线了 对画线部分进行提问( ) have they ( )( )for 10 years?