China’s Beidou global satellite navigation system will have been completed by 2020, ____ of more than 30 satellites.
After completing and signing it, please return the form to us in the envelope ________.
_______the Teachers’ Day ,the students are cleaning the classroom.
I need to get another dictionary, because cover is dirty and page is missing.
—I often see him working hard in his spare time. —________he has won the scholarship from time to time.
Years ago we didn't know this, but recent science study ________that people who don't sleep well soon get ill.