My uncle __________ around the United States for six months. (TRAVEL)
has been traveling
The lights in that building ________ on and off all evening. (GO)
have been going
I'm sorry I'm covered in mud - I __________ in the garden all morning. (WORK)
have been working
We _________ English for many years. (STUDY)
have been studying
He is completely exhausted. He __________ for a few hours. (CLIMB)
has been climbing
It __________ for many days. I wonder when it will stop raining. (RAIN)
has been raining
Lately I _________ a lot about Christmas. (THINK)
have been thinking
She __________ at the animal shelter for a long time. (VOLUNTEER)
has been volunteering
Jim __________ since he was six. (SWIM)
has been swimming
Over the last month, I _______ hard for my next marathon. (TRAIN)
have been training