10 sentences

1. 这两条直线是平行的。

   zhè liǎng tiáo zhí​xiàn shì píng​xíng de.

   These two straight lines are parallel.

   Source: Dong Chinese Dictionary

2. 他在墙上画了一条直线。

   tā zài qiáng shàng huà le yī tiáo zhí​xiàn.

   He drew a straight line on the wall.

   Source: Tatoeba

3. 这两条直线在圆心相交。

   zhè liǎng tiáo zhí​xiàn zài yuán​xīn xiāng jiāo.

   These two lines intersect at the center of the circle.

   Source: Dong Chinese Dictionary

4. 在这里画一条直线。

   zài zhè​lǐ huà yī tiáo zhí​xiàn.

   Draw a straight line here.

   Source: Tatoeba

5. 这条直线与圆相切。

   zhè tiáo zhí​xiàn yǔ yuán xiāng qiē.

   This straight line is tangent to the circle.

   Source: Dong Chinese Dictionary

6. 这两条直线在圆心处相交。

   zhè liǎng tiáo zhí​xiàn zài yuán​xīn chù xiāng​jiāo.

   These two straight lines intersect at the center of the circle.

   Source: Dong Chinese Dictionary

7. 这两点之间可以连成一条直线。

   zhè liǎng diǎn zhī​jiān kě​yǐ lián​chéng yī tiáo zhí​xiàn.

   A straight line can be drawn between these two points.

   Source: Dong Chinese Dictionary

8. 任意两点之间可以画一条直线。

   rèn​yì liǎng diǎn zhī​jiān kě​yǐ huà yī tiáo zhí​xiàn.

   A straight line can be drawn between any two points.

   Source: Dong Chinese Dictionary

9. 入冬以来，气温直线下降。

   rù​dōng yǐ​lái, qì​wēn zhí​xiàn xià​jiàng.

   Temperatures have plummeted since the beginning of winter.

   Source: Dong Chinese Dictionary

10. 现在图书销量直线下降。

    xiàn​zài tú​shū xiāo​liàng zhí​xiàn xià​jiàng.

    Book sales are plummeting right now.

    Source: OpenSubtitles