我在学校是好菇凉我在学校是好少年
[wŏ zài xué xiào shì hăo gū liáng wŏ zài xué xiào shì hăo shăo nián]
The phrase means 'I am a good girl/boy at school.' It describes a student who behaves well, is respectful, follows rules, and is generally a model pupil. There’s redundancy in using both terms which adds emphasis.