The quantities given in the Bill of Quantities are estimated and provisional, and are given to provide a common basis for bidding. The basis of payment will be the actual quantities of work ordered and carried out, as measured by the Contractor and verified by the Engineer and valued at the rates and prices bid in the priced Bill of Quantities, where applicable, and otherwise at such rates and prices as the Engineer may fix within the terms of the Contract. The rates and prices of major materials (steel pipes, electromagnetic meters and valves) will be paid upon delivered to the site according to the related items in the Technical Specifications.这段谁能翻译下？不懂

Bill of Quantities 即BOQ，工作量清单
The quantities given in the Bill of Quantities are estimated and provisional, 在BOQ中列出的工作量是估计值和原则性的，and are given to provide a common basis for bidding. 用作投标时的参考基数。The basis of payment will be the actual quantities of work ordered and carried out付款将依据实际发生的工作量, as measured by the Contractor and verified by the Engineer and valued at the rates and prices bid in the priced Bill of Quantities由承包商报出并由业主的项目总工核实，并根据BOQ中注明的单价来计算总值, where applicable（在可行的情况下）, and otherwise at such rates and prices as the Engineer may fix within the terms of the Contract（不然就由业主工程师在合同条款当中来规定这些单价）. The rates and prices of major materials (steel pipes, electromagnetic meters and valves) will be paid upon delivered to the site according to the related items in the Technical Specifications（主材的单价（钢管，电磁表，电磁阀））将根据技术合同当中的相关条目来拨付给现场。