17.A根据第4段可知,送奶工消失了,是因为大型奶企的牛奶更便宜,到处都可以买得到。18.B根据最后一段可知,一个旧订奶箱激起了作者童年的回忆,所以他把它带回来放在后门廊上。写作第一节One possible version:Dear Peter,I'm Li Hua from Class 1,Senior 3.I would like to submit an amazing photograph I tooklast week for the exhibition.It captured a heartwarming scene in a nursing home,where someof my classmates were dishing out hot meals and others were having lively conversations withthe elderly.All their faces were bright with smiles and glowing with happiness,creating awarm and loving atmosphere.