backward and forward：phr. 忽前忽后，来回地，前后地，前前后后(moving from one place to another and back again)。同义词：back and forth，to and fro。
【例句】
The car passed over the body twice, once backward and then forward.
那辆车把那人来回轧了两次，先是倒着轧的，再是往前开着轧的。
Of course we can go backward and forward in time.
我们当然能在时间中自由来回。
