求翻译：建筑材料的价格从投标、中标到实施采购，可能需要经历比较长的时间，而建筑市场的材料价格受政治、经济等很多因素影响，波动较大。全球金融危机、国际原油价格的变化以及国际货币市场汇率波动等，对建筑材料的价格均有重大影响，这些因素都增大了对材料价格预测的难度。是什么意思？

Price from bid in a tender, to the implementation of the procurement of building materials, you may want to experience a relatively long time, and building materials in the market price is affected by many factors, including political, economic, and volatile. Changes in the global financial crisis, the International crude oil prices and exchange rate fluctuations, such as the international currency market, have a significant impact on the prices of building materials, these factors have increased the difficulty of material price forecast.