He lived in London for 3 months, during ____ time he learned some English.
The black colour of your shoes doesn’t_______ the white colour of your suit.
Mr.Smith was much surprised to find the watch he had had _______was nowhere to be seen.
Only when class began _______that he had left his book at home.
The students in this college are all taking courses _______a degree.
----You can’t finish the book in less than an hour, I suppose? -----________.