事关紧要 meaning in English

itmattersmuch

If there is an extraordinary reason why you must keep your phone on ( e . g . , you are awaiting critical medical news ) please silence your phone and let your professor know in advance that you may receive a call
如果事关紧要（比如等医院的诊断结果）不得不开机，请置静音，而且事先应告知你的教授你可能要接听一个电话。
After wandering along the lane for two hours , giving way to every variety of thought ; re - considering events , determining probabilities , and reconciling herself , as well as she could , to a change so sudden and so important , fatigue , and a recollection of her long absence made her at length return home ; and she entered the house with the wish of appearing cheerful as usual , and the resolution of repressing such reflections as must make her unfit for conversation
她沿着小路走了两个钟头，前前后后地左思右想，又把好多事情重新考虑了一番，判断一下是否确有其事。这一次突然的变更，实在事关紧要，她得尽量面对事实。她现在觉得疲倦了，又想到出来已久，应该回去了她希望走进屋子的时候脸色能象平常一样愉快，又决计把那些心思抑制一下，免得跟人家谈起话来态度不自然。