5 sentences

1. 宪兵正在大门口站岗。

   xiàn​bīng zhèng​zài dà​mén​kǒu zhàn​gǎng.

   The military police are standing guard at the gate.

   Source: Dong Chinese Dictionary

2. 他今天在军营大门口值门卫。

   tā jīn​tiān zài jūn​yíng dà​mén​kǒu zhí mén​wèi.

   He is on guard duty at the main gate of the barracks today.

   Source: Dong Chinese Dictionary

3. 他在大门口徘徊，似乎在等人。

   tā zài dà​mén​kǒu pái huái, sì​hū zài děng rén.

   He was pacing back and forth at the gate, seemingly waiting for someone.

   Source: Dong Chinese Dictionary

4. 我睇见他从大门口急匆匆地走进去了。

   wǒ dì jiàn tā cóng dà​mén​kǒu jí​cōng​cōng de zǒu​jìn​qù le.

   I saw him rushing in through the main gate.

   Source: Dong Chinese Dictionary

5. 走到大门口，他突然想起了什么，猛地站住了。

   zǒu dào dà​mén​kǒu, tā tū​rán xiǎng​qǐ le shén​me, měng​de zhàn​zhù le.

   As he reached the main gate, he suddenly remembered something and came to an abrupt halt.

   Source: Dong Chinese Dictionary