她从早上8点到夜间7点都在工作
如果说的是某一天的话：She's been working from 8 a.m.to 9 p.m..
或 She has been working from 8 in the morning to 7 in the evening.
如果说的是每天都如此的话：She works from 8 a.m.to 9 p.m..
或 She works from 8 in the morning to 7 in the evening.
他在西安工作 He works in Xi'an.