2. The average length of labor during which these women received their meperidine was under 12 hours.
4. Socially Awkward Situations During Which It Would Be Acceptable to Mess With Texas.
5. Fish evolve a longer lifespan by evolving a longer period during which they reproduce.
4. Have been fostering for five years, during which time they have fostered 20 children.
5. ... registry will occur on 9/24/2006 from 9 PM to 9:45 PM EDT, during which time you will be unable to register, renew or manage .
這些都是google上搜到的原版英文句子,可以看出一個規(guī)律,during which的中心語大部分是表示時間段的名字例如period等；而duiring which time的中心語常常是具體的時間如5 years等.
具體的原理我不記得了,希望這樣的對比能對你有所啟發(fā).