--------Will you go skiing with me this winter vacation?---------It ______.
You have to explain ____ us the reason _____ your being absent from school yesterday.
There are two thousand students in this college, ______ are from the countryside.
---How can you keep slim as a mother of two sons?---I _______ in the gym for years.
In the past ten years, the ____mountain climber ____ a lot from his own adventurous _______
The average temperature this year is _______ that of last year.