I provide a service that people can do without when they’re concerned about saving some dollars.
首先,我不得不說,你真細(xì)心!這種探求精神正是學(xué)習(xí)所需!
其次,理論上講,【在口語和非正式語體中,關(guān)系代詞在從句中作賓語時(shí)經(jīng)常省略】.如：
The story (that/which)he told us is instructive.
按照此語法補(bǔ)充,你所給的句子【在口語和非正式語體中時(shí)】,that可以省略.
但是,【如果省略關(guān)系代詞容易導(dǎo)致誤解或費(fèi)解時(shí)】,最好不省略.因?yàn)?語言的主要功能是交際,準(zhǔn)確的傳達(dá)信息才是終極目的.
最后,需補(bǔ)充的是,所給句子里,如果將介詞without提前,那關(guān)系代詞需用which,且絕對(duì)不可省略.即：
I provide a service without which people can do when they’re concerned about saving some dollars.