I still remember when I was eight, I had a bad stomachache.

我还记得八岁的时候，我胃痛得很厉害。

youdao

Second, try not to breathe in through your mouth directly when running, because of the cold air directly into the abdominal cavity, easy to catch a cold, have a stomachache, so should be shut up.

其次，跑步时尽量不要用嘴直接吸气，因为冷空气直接进入腹腔，容易着凉，肚子疼，所以应闭上嘴才好。

youdao

Second, try not to breathe in through your mouth directly when running, because of the cold air directly into the abdominal cavity, easy to catch a cold, have a stomachache, so should be shut up.

其次，跑步时尽量不要用嘴直接吸气，因为冷空气直接进入腹腔，容易着凉，肚子疼，所以应闭上嘴才好。

youdao