—How was your recent trip to Sichuan?—I've never had __________ one before.
The new comers found it impossible to________ themselves to the climate sufficiently to make permanent homes in the new countries.
He followed the young lady all the way home,________ by her charming smile.
It's not necessary to explain the truth________there are air,water and sunlight,there are living things.
Tomorrow is Tom's birthday. Have you got any idea________the party is to be held?
Along with the letter was his promise________he would visit me this coming Christmas.