答案正确.
1.在英语中,经常会有如下结构:one's doing sth=sb(宾格) doing sth,该结构相当于名词短语.
2.如:Do you mind my smoking?= Do you mind me smoking?
This is a photo of my standing on the desk.=This is a photo of me standing on the desk.
3.How/What about...句型中about是介词,所以其后只能加上名词性的短语.
two of us watering the flowers in the garden即 sb(宾格) doing sth,相当于名词短语,做介词about的宾语.