原文Break Under Pressure targets only the opponent, not any permanent. A permanent with hexproof may be sacrificed this way if its mana value is the greatest, for example.
原文Consider all creatures and planeswalkers the target opponent controls as one group to see which one has the greatest mana value. For example, if the opponent controls a creature with mana value 3 and a planeswalker with mana value 5, they must sacrifice the planeswalker.