while表示的时间是一段,而不是一个时间点,如:While he was eating his breakfast,he heard the doorbell ring.(强调吃饭的过程)
as强调“同一时间”,或“一前一后”发生的事,
she was getting off the train就是强调她下火车的那一个时间点,而不是一段时间
while表示的时间是一段,而不是一个时间点,如:While he was eating his breakfast,he heard the doorbell ring.(强调吃饭的过程)
as强调“同一时间”,或“一前一后”发生的事,
she was getting off the train就是强调她下火车的那一个时间点,而不是一段时间