stomach ache

我肚子疼，所以没去上学。

I had a ___stomach ___ache, so I didn't go to school.

如果你肚子疼，就喝点温水。

If you have a ___stomach ___ache, drink some warm water.

我妹妹经常肚子疼。

My sister often gets ___stomach ___aches.

医生问我肚子疼了多久。

The doctor asked me how long I've had the ___stomach ___ache.