Does going to Columbia University (tuition, room and board $49,260 in 2007-08) yield a 40% greater return than attending the University of Colorado at Boulder as an out-of-state student ($35,541)? (09.6 Passage 2)
主干：Does going to...yield a...greater return than attending...?
1.本句是简单疑问句，比较句型，两个动名词短语going to...和attending...进行比较，这两个动名词都接了某个大学的名字作宾语，所以主干的含义是：难道上A大学比上B大学多出40%的受益吗?yield a return “产生利益回报，产生收益”。
2.括号里的内容分别说明上两所大学的费用。句末as引导的介词短语作状语，表示身份。
