The long-term effects of bad presents are still unknown.
糟糕的礼物对二人关系的长期影响依然尚未知晓。
Another unknown: how long will the treatment effects last?
还有一点不得而知：疗效能持续多久？
The effects of brain activity being artificially stimulated are still unknown.
这种人为刺激大脑活动带来的影响仍然不清楚。
Unknown to many people, herbal remedies can cause serious side effects in some patients.
很多人都不知道，草本疗法可能会对患者造成严重的副作用。
Unknown to many people, herbal remedies can cause serious side effects in some patients.
很多人都不知道，草本疗法可能会对患者造成严重的副作用。
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