Was it through Mary, _____ was working at a high school, ____ you got to know Tom?

Congratulations! You’re chosen to be an exchange student to Britain.—

(2013·高考江苏卷)I should not have laughed if I________ you were serious

It is known to all that every minute _____ full use of ______ the lessons will benefit students a great deal [ ]

Detective Sam Peterson told the journalists ________ they hadn’t dismissed the idea that Justin was taken away by the aliens, they were looking into other possibilities.