Your stomach sinks, you have that sinking feeling in the pit of your stomach, when you get a bad grade on a test.

当你考试考砸的时候,你的胃会垂下去,或者说,会有胃部下垂的感觉

耶鲁公开课 - 死亡课程节选

When you're afraid, you've got this sinking feeling in the stomach.

当你害怕时,你会有胃部下沉的感觉

耶鲁公开课 - 死亡课程节选