七 + Classifier + Noun
The numeral 七 (qī) represents the number seven. Like all Chinese numerals, it must be followed by a classifier when used with a noun. For example, 七场比赛 means 'seven matches,' where 场 is the classifier for events.
这个星期我看了七部电影。
Zhège xīngqī wǒ kàn le qī bù diànyǐng.
I watched seven movies this week.
她家里养了七只猫。
Tā jiālǐ yǎng le qī zhī māo.
She has seven cats at home.
我们班有七个男生。
Wǒmen bān yǒu qī ge nánshēng.
There are seven boys in our class.