— Hi, Johnson, any idea where Susan is ? — It’s class time, so she________in the classroom now.
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.