①In/Under the circumstances, we must rely on ourselves.
②Under no circumstances should you lend him any money.
③You must leave your position under/in no circumstances.
→In/Under no circumstances must you leave your position．
[名师点津]
以下短语均意为“决不；无论如何也不”，置于句首时，句子要用部分倒装语序。
at no time, in no way, in no sense, on no account, on no condition
