Turn your back on sb/sth (idiom)

　　●If you turn your back on someone or something, you ignore them, leave them, or reject them.（不理會）

　　Examples:　　

　　1.He said the nation had turned its back on the poor for many years.　　

　　2.He simply turned his back on them and never gave it a second thought.

　　Stand by (phrasal verb)

　　●To be waiting and ready to do something. （準備好隨時行動）

　　Examples:　　

　　1.Could you stand by in case I need help?　　

　　2.Fire fighters were standing by in case of emergencies.

　　Seditious (adj.)

　　●Inciting or causing people to rebel against the authority of a state or monarch.（煽動性的）

　　Examples:　　

　　1.She was arrested after making a speech that the government considered to be seditious.　　

　　2.The letter was declared seditious.

　　Plunge into sth (phrasal verb)

　　●To suddenly start doing something with energy and enthusiasm, but sometimes without thinking about it first.（投入……，一頭扎進……）

　　Examples:　　

　　1.This was not the time to be plunging into some new business venture.　　

　　2.Two months before his exams, he suddenly plunged into his studies.

　　Destined (adj.)

　　●controlled by fate, and not by humans.（注定）

　　Examples:　　

　　1.These plans are destined to fail.　　

　　2.Do you think it was destined that we should one day meet?