7 sentences

1. 沧海茫茫，一眼望不到边。

   cāng​hǎi máng​máng, yī yǎn wàng bù dào biān.

   The vast blue sea stretches as far as the eye can see.

   Source: Dong Chinese Dictionary

2. 茫茫的大海一眼望不到边。

   máng​máng de dà​hǎi yī yǎn wàng bù dào biān.

   The vast, boundless sea stretches beyond the horizon.

   Source: Dong Chinese Dictionary

3. 在茫茫人海中，能与你相遇是一种缘分。

   zài máng​máng rén​hǎi zhōng, néng yǔ nǐ xiāng​yù shì yī zhǒng yuán​fèn.

   In the vast sea of people, it is fate that we met.

   Source: Dong Chinese Dictionary

4. 这艘货轮在茫茫大海中正奋力向东航。

   zhè sōu huò​lún zài máng​máng dà​hǎi zhōng zhèng fèn​lì xiàng dōng háng.

   The freighter is laboring eastward through the vast ocean.

   Source: Dong Chinese Dictionary

5. 古人在茫茫大海上常根据北斗的方向来辨别南北。

   gǔ​rén zài máng​máng dà​hǎi shàng cháng gēn​jù Běi​dǒu de fāng​xiàng lái biàn​bié nán​běi.

   Ancient people often relied on the direction of the Big Dipper to tell north from south at sea.

   Source: Dong Chinese Dictionary

6. 他一直渴望在茫茫人海中寻得一位可以倾诉衷肠的良知。

   tā yī​zhí kě​wàng zài máng​máng rén​hǎi zhōng xún​dé yī wèi kě​yǐ qīng​sù zhōng​cháng de liáng​zhī.

   He has always longed to find a soulmate among the crowd to whom he can open his heart.

   Source: Dong Chinese Dictionary

7. 他对未来的前途感到一片茫茫。

   tā duì wèi​lái de qián​tú gǎn​dào yī piàn máng​máng.

   He felt that his future prospects were vague and uncertain.

   Source: Dong Chinese Dictionary