如题所述
My mother is _____ ( dancer ) with her friends. 根据句意和所给题型可断定这是要求填写dancer的正确形式,后面有介词短语with her friends (和她的朋友一起),空白处显然要填dancer的动词形式,故填dancing 。My mother is dancing with her friends. 我母亲在和她朋友们一起跳舞。