是by sth for

是by sth for by sth for sb. by sth for sb by sth.to sb.还是by sth.for sb. by sth ______ sbby sth ______ for sbby sth ______ to sb分别用在什么地方 be divided 和divided sth.into sth.separate sth.和divide sth.有什么区别吗?各是怎么用的?By the way,keep sth./sb.from doing是表示阻止……干什么事吗?还有一个,get sb.for sth.如何翻译?eg.What should I get my mom for her bi 是use sth for doing sth还是use sth doing sth by sb sth 和 buy sth for sb 意思一样吗?用法一样吗? prepare sth for sth see sth.onself see sth.for onself see sth.by oneself这三个词组之间有什么区别?…… 是make sth to sb还是make sth for sb? 是send sth to sb 还是send sth for sb 是leave sth.to sb.还是leave sth.for sb. 是feed sth to sb还是feed sth for sb? 是provide sb.for sth还是provide sb with sth? 是sing sth.to sb.还是sing sth.for sb. make a plan是of sth 还是for sth 是arrange sb for sth还是arrange sb with sth