2 sentences

1. 士兵在黑暗中喊道：“站住！对暗号！”

   shì​bīng zài hēi'àn zhōng hǎn​dào:“ zhàn​zhù! duì àn​hào!”

   The soldier shouted in the dark, 'Halt! Give the password!'

   Source: Dong Chinese Dictionary

2. 他们约定好以窗台上的花盆作为暗号。

   tā​men yuē​dìng​hǎo yǐ chuāng​tái shàng de huā​pén zuò​wéi àn​hào.

   They agreed to use the flowerpot on the windowsill as a signal.

   Source: Dong Chinese Dictionary