两个介词的英语句子怎么翻译

『壹』 用英语中的介词造6个句子(加翻译)

He is at work. 他正在工作。
The road isunderconstruction. 路正在修。
Our teacher stands in the front of the classroom. 我们的老师站在教室前
I studied in this university for 4 years, ring that time most of my time was spent in learning English. 我在这所大学学习了内4年，在那段时容间里，我大部分时间都花在学英语上了。
Most people work from nine to five. 多数人过着朝九晚五的生活
I killed a fly with a fly flap.
我用苍蝇拍打死了一只苍蝇