under no circumstances什么意思解释？

under no circumstances的音标：...

Under no circumstances can we agree to such a principle.在任何情况下我们都不能同意这一原则.Under no circumstances should we lose sight of our main objective.在任何情况下,我们都不能忘记自己的宗旨.We must under no circumstances take this lightly.这事儿千万不可掉以轻心...