求翻译：2 、甲方同意当实测面积与暂测面积的误差超过+3%（包括3%），不向乙方收取超过部分的房价款；甲方同意当暂测面积实测面积的误差超过-3%（包括-3%），乙方有权单方面除本合同。乙方行使单方解除权时，必须在双方签署《房屋交接书》之时之前提出，否则视为放弃该项权利。是什么意思？

2, party a agrees when the measured area and temporary errors in measuring area of more than +3% (including 3%), not to party b charge more than part of the price; the Party agreed to when the temporary measuring area measured area of error than-3% (includes-3%), party b has the right to unilaterall