3 sentences for 必 (bì — must)

1. 欲王天下者，必先修其德。

   yù wàng tiān​xià zhě, bì xiān xiū qí dé.

   Those who wish to rule the world must first cultivate their virtue.

   Source: Dong Chinese Dictionary

2. 想要取得成功，必先经历一番刻苦努力。

   xiǎng​yào qǔ​dé chéng​gōng, bì xiān jīng​lì yī fān kè​kǔ nǔ​lì.

   To achieve success, one must first go through a period of hard work.

   Source: Dong Chinese Dictionary

3. 这种美式烤猪排的味道非常好，是这家餐厅必点的招牌菜。

   zhè zhǒng Měi​shì kǎo zhū​pái de wèi​dao fēi​cháng hǎo, shì zhè jiā cān​tīng bì diǎn de zhāo​pái​cài.

   These American-style BBQ pork ribs taste excellent and are a must-order signature dish at this restaurant.

   Source: Dong Chinese Dictionary