“先兆的”用英语怎么说？

它会毫无先兆的发生.It can happen without warning.偏头痛发作, 尤其是有先兆的偏头痛, 是主要的预测因素.The presence of migraine attacks, especially migraine with aura , was the major predictor for these associations.有先兆的偏头痛比无先兆偏头痛具有和精神障碍更强的相关性.The associa...