'if you feel any pain you should stop or if you have any pre-existing physical vulnerability, then you should always get medical advice before trying it,' he says. 'Yoga can reduce stress levels.

如果你感觉到疼你就应该立刻停止，或者你之前有受过什么伤，你就应该在做瑜伽之前咨询一下专业医师。

youdao

In general, a higher pre existing microcrack density or a lower loading stress rate results in a longer nucleation stage, and therefore, increases the predictability of catastrophic failure event.

一般而言，在相同加载条件下预存微破裂密度越高，或对同一岩石加载速度越慢，对应的断层成核过程就越长，因此最终破坏的可预报性也越高。

youdao

The person who initially found the envelope is being treated at a Phoenix-area hospital for a pre-existing condition and stress from the event, and others in the immediate vicinity were examined as well.

CNN: Feds: Mississippi man arrested in ricin scare

Rebecca Wood, chief executive of the Alzheimer's Research Trust, said it was important to stress that the study only focussed on people with pre-existing memory conditions.

BBC: Money problems 'signal dementia'