During the time we made a model plane, lots of things __________.

Festival is the most importantfestival in China and an occasion ____ all family members get together, justlike Christmas in the West.

Have you decided ___________ the children in the poor areas–By sending them books and schoolbags.

______ teacher and _____ student has been invited. Which is wrong? [ ]

The course books are _____ by four tapes, which are beneficial to beginners.