self-assured or supercilious

pick and choose - tiāo sān bō sì

rack one's brains - shà fèi kǔ xīn

Haggard - qiáo shén cuì lì

The bell tolls at the end of the day - dǐng shí míng zhōng

I'm convinced - xīn fú shǒu kěn

Yunjintianzhang - yún jǐn tiān zhāng

It's easy to make a plan - gé tú yì lǜ

Study hard - yán jīng kǔ sī

give up - shàn bà gān xiū

most suitable and not subject to change - zhì dàng bù yì