1.（ ）He had ____yesterday .He saw a snake at his foot at his foot,and he was very scared.
A.an experience B、a experience
C experience D experiences
2.( )Can you imagine ____as a doctor?
A work B to work C working D worked
3.( )It makes them happy and his room is always full _____children when he is free.
A with B for C of D by