4 sentences

1. 糖浆冷却后开始结晶。

   táng​jiāng lěng​què hòu kāi​shǐ jié​jīng.

   The syrup began to crystallize as it cooled.

   Source: Dong Chinese Dictionary

2. 塑料在模具中冷却后即可成型。

   sù​liào zài mú​jù zhōng lěng​què hòu jí kě chéng​xíng.

   The plastic can be molded once it cools in the mold.

   Source: Dong Chinese Dictionary

3. 熔化的岩浆冷却后会凝固成岩石。

   róng​huà de yán​jiāng lěng​què hòu huì níng​gù chéng yán​shí.

   Molten magma solidifies into rock after cooling down.

   Source: Dong Chinese Dictionary

4. 我们需要等发动机冷却后再检查。

   wǒ​men xū​yào děng fā​dòng​jī lěng​què hòu zài jiǎn​chá.

   We need to wait for the engine to cool down before checking it.

   Source: Dong Chinese Dictionary