When I ______to take part in the sport, I felt very surprised because I had never done this before. 

 Though ________ in San Francisco, Dave Mitchell had always preferred to record the plain facts of small-town life.

 As I______ the little grass house in the forest, my heart beat more and more quickly.

It suddenly        to the teacher that he hadn’t left any assignments(作业) to his students.

— Why does he walk like that? It seems that he has great difficulty in walking.  — Because he got ____ in an accident three years ago.