“Lily is preparing dinner” 意思是丽丽正在准备晚餐。
这句话的来源是结合了两个英文动词：“Lily”（丽丽）和“is preparing”（正在准备）。
例句：
"Lily is preparing dinner for her family tonight." (丽丽今晚正在为她的家人准备晚餐。)
"John is helping Lily prepare dinner." (约翰正在帮助丽丽准备晚餐。)
"Lily is in the kitchen preparing dinner, do you want to join her?" (丽丽正在厨房准备晚餐，你想和她一起吗？)