_____ the catastrophe happened that the local government realized the importance of substantial development.
This is the first time we ________ a film in the cinema together as a family.
Why didn’t David ________his friend’s invitation to the picnic?—Because he had to prepare for the exam.
________ May 27 th, 2008, millions of people watched the Beijing Olympic Torch Relay in Nanjing. [ ]
How do you study _______ a test?[ ]