知识点：否定或限制性副词短语置于句首时，需要倒装。
助动词置于句首。实义动词不要置于句首。
Not only
Little – When Marta signed the lease,little did she realize how noisy the street was.
Rarely 几乎不 – During the budget meeting,rarely did Priya complain about small delays.
Under no circumstances – For safety reasons, under no circumstances may staff leave this door unlocked.
Never – In all my years here,never have I seen the river this high.
Scarcely – Scarcely had Jia sat down when the baby wokeup.
Only + 状语（only once）置于句首
Only when – Only when the bell rang did they put their books away.
Only once – Only once have we rented skis here.
Only late – Only later did(do) I notice the scratch on the lens.
No sooner – No sooner had the meal ended than the lights went out.
At no point – At no point did(do) the guide mention an extra fee.
Nowhere else – No where else could we find a room that cheap.
Seldom – Seldom do (do) I use cash anymore.