3 sentences

1. 恒星是由炽热气体组成的。

   héng​xīng shì yóu chì​rè qì​tǐ zǔ​chéng de.

   Stars are made of hot gas.

   Source: CCMatrix

2. 1、早在中世纪，许多人就相信火山是进入炽热的地下世界的入口。

   1, zǎo​zài zhōng​shì​jì, xǔ​duō rén jiù xiāng​xìn huǒ​shān shì jìn​rù chì​rè de dì​xià shì​jiè de rù​kǒu.

   During the Middle Ages, many people thought volcanoes were the entrance to the fiery underworld.

   Source: CCMatrix

3. 荧光灯的使用寿命要比白炽灯长。

   yíng​guāng​dēng de shǐ​yòng shòu​mìng yào bǐ bái​chì​dēng cháng.

   Fluorescent lamps have a longer service life than incandescent lamps.

   Source: United Nations