A new library is being built _______ there was a playground .
My study of biology has ___ much of my spare time, ____ it has given me a great deal o enjoyment.
The doctor will be free ___.
__ is known to everybody, the moon travels round the earth every month.
---I drove to Zhuhai for the air show last week.---Is that ___ you had a few days off?
What the doctor really doubts is ___ my mother will recover from the serious disease soon.