1.While Lady Crawford was in the hospital, she emailed Ms. White. While Ms. White was in the hospital, Lady Crawford emailed her.
2.When Tidus was overseas on deployment, he reported to his supervisor. While his supervisor was overseas on deployment, Tidus reported to him.
3.While Sarah was on vacation, she offered to clean Mariah's apartment. While Mariah was on vacation, Sarah offered to clean her apartment.
4.Since Beth had lost her watch, both she and Melissa were late. Because Melissa had lost her watch, both she and Beth were late.