rancid

这双运动鞋已经穿了很久，散发出难闻的味道。

These sneakers have been worn too long and now have a ___rancid smell.

冰箱里那瓶牛奶已经变质了，散发出难闻的气味。

The milk in the fridge has turned ___rancid and smells terrible.

这瓶油放了太久，闻起来有股酸臭味。

This bottle of oil has been stored too long and now smells ___rancid.