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질문
while th boy was walking to school, he saw lots of dogs.

이문장을 분사구문으로 바꾸면

being walking to school, he saw lots of dogs. 아닌가요 ??
그런데 책에는 walking to school, he saw lots of dogs. 가 답이라고 나와서요.

그리고 helping my parents wash the car, i fell down.
을 부사절로 바꾸면
왜 whilw i was helping, i fell down. 이 되는지 궁금해요
while 대신 when을 쓰면 틀리나요 ??

그리고 sitting in class, she kept talking with her friend. 가
왜 while i was sitting in class, she kept talking with her friend.로 되는지 이해가 안되요.
while 대신에 when은 쓸수없는건가요 ???