3 sentences

1. 北方人冬天习惯囤积白菜。

   běi​fāng​rén dōng​tiān xí​guàn tún​jī bái​cài.

   People in northern China are used to stockpiling Chinese cabbage in winter.

   Source: Dong Chinese Dictionary

2. 由于担心物资短缺，不少家庭开始囤积生活必需品。

   yóu​yú dān​xīn wù​zī duǎn​quē, bù​shǎo jiā​tíng kāi​shǐ tún​jī shēng​huó bì​xū​pǐn.

   Concerned about shortages, many families began to stockpile daily necessities.

   Source: Dong Chinese Dictionary

3. 有些商人在灾荒期间囤积粮食，哄抬物价。

   yǒu xiē shāng​rén zài zāi​huāng qī​jiān tún​jī liáng​shi, hōng​tái wù​jià.

   Some merchants hoarded grain and jacked up prices during the famine.

   Source: Dong Chinese Dictionary