He did many situps at the gym.

他在健身房里做了很多仰卧起坐。

Every morning, I do 20 situps.

每天早上我都会做20个仰卧起坐。

Situps are a great way to work out your abs.

仰卧起坐是锻炼腹肌的好方法。

I find situps difficult, but I will keep trying.

我觉得仰卧起坐很难，但我会坚持。

The coach advised me to do some situps every day.

教练建议我每天做一些仰卧起坐。