providesthtosb还是for,bringsthtosb还是forsb

i'll need to buy a large backpack to carry my supplies of food
buy sth for sb 可以改为buy sb sth为什么要这样改?ppt
中考英语语法总复习1 语法概述 第1课 语法是什么-图片
buy sth for sb.
arrange for sb to do 4.be known as 5.take over 6.