From space, the earth looks blue.This is ________about seventyone percent of its surface is covered by water.
Mr Chen was ___ early thirthies when he went abroad to have his further studies.
Children often get presents ___ Christmas and ___ their birthdays.
You can find the new hospital ___ the end of the street.
___ the end of this new term we'll have graducated from middle school.
The mid-term exam is to be held ___ the end of this month.