警官正在调查案件。
jǐngguān zhèngzài diàochá ànjiàn 。
The police officer is investigating the case.
我们需要呼叫警官来帮助我们。
wǒmen xūyào hūjiào jǐngguān lái bāngzhù wǒmen 。
We need to call the police officer to help us.
警官向市民解释了新规章。
jǐngguān xiàng shìmín jiěshì le xīn guīzhāng 。
The police officer explained the new regulations to the citizens.