凡句中有下列副詞片語出現時,動詞均採現在完成式或現在完成進行式

since

over

during      +the past / the last +數字+ years/months/days

through

for

例:

He had been working very hard over the past five hours.

例:

Over the last ten years, the nubmer of people entering managerial roles has increased significantly.