Some people get in touch with each other by mobile phones__________ others keep contact with each other by e-mail. A. while B. before C .when C. since
—We were surprised to hear that the reason_______ she gave for her absence was______ her mother was ill. —Yes,we saw her mother was at the supermarket that morning.
—I wonder what makes you a successful manager. —I ________ as a waiter for five years,which contributes a lot to my today’s work.
Due to the widespread ________ of this medical technology,more diseases can be discovered and treated at an early stage.
The book was written ______ careful observations and detailed studies.
You had better ______some time every day for sports so that you can keep yourself energetic.