为更专门的工作
为晋升的前途
为更高层次的工作责任　　
为扩大工作经验
找一份更好的工作
由于雇用期满
找到了更好的工作
由于公司倒闭
for more specialized work
for prospects of promotion
for higher responsibility
for wider experience
to seek a better job
due to expiry of employment
sought a better job
due to close-down of company