离职原因： for more specialized work 为更专门的工作 for prospects of promotion 为晋升的前途 for higher responsibility 为更高层次的工作责任 for wider experience 为扩大工作经验 due to close-down of company 由于公司倒闭 due to expiry of employment 由于雇用期满 offered a more challenging opportunity 获得的更有挑战性的工作机会 sought a better job 找到了更好的工作 to look for a more challenging opportunity 找一个更有挑战性的工作机会 to seek a better job 找一份更好的工作