HSK 3
Kuòhào lǐ de nèiróng shì bǔchōng shuōmíng.
The content in parentheses is supplementary explanation.
HSK 5
Tā zài guānjiàn de dìfang jiā le kuòhào.
He added brackets at the key spot.
HSK 7-9
Qǐng zài kuòhào lǐ tiánxiě dá'àn.
Please write the answer in the brackets.