You won"t see a change immediately and you may need to build up to doing 10-15 sit-ups a day."

如果其它方法不能立竿见影，那么可以考虑每天做10-15分钟的仰卧起坐。

youdao

You won"t see a change immediately and you may need to build up to doing 10-15 sit-ups a day."

如果其它方法不能立竿见影，那么可以考虑每天做10-15分钟的仰卧起坐。

youdao