17．承包人負責按工程師提交的書面參考原圖的有關點、線和面的規定，忠實恰當地進行測定放線，如上所述，使工程的位置、水平、面積正確無誤，並校準工程的各部分，且負責提供與工程相關的所有必要工具、設備和勞力。在施工中，如任何時候在工程的位置、水平、面積或工程任何部分的校正出現差錯，應工程師或工程師代表的要求，承包人必須改正錯誤以使工程師或工程師代表滿意，改正費用由承包人自己承擔，此種錯誤是由工程師或工程師代表提供的書面資料差錯而導致的除外，在這種情況下，須由業主承擔改正費用。承包人不得因工程師或工程師代表對任何位置測定或任何線或任何水平面的檢查而免去確保其正確無誤的責任，承包人必須仔細保護和保存工程位置測定中使用過的水準點、觀測桿、測標及其他物品。
18．if，at any time during the execution of the works，the engineer shall require the contractor to make bore holes or to carry out exploratory excavation，such requirement shall be ordered in writing and shall be deemed to be an addition ordered under the provisions of clause 51 hereof，unless a provisional sum in respect of such anticipated work shall have been included in the bill of quantities．
18．在施工中，工程師如在任何時間要求承包人鑽孔或進行挖掘勘探，此種要求必須作成書面形式，且得視為是根據本契約第51條規定作出的附加命令，除非數量清單中已經列有有關此種預計工程的備用款。
19．the contractor shall in connection with the works provide and maintain at his own cost all lights，guards，fencing and watching when and where necessary or required by the engineer or the engineer's representative，or by any duly constituted authority， for the protection of the works，or for the safety and convenience of the public or others．
19．凡有必要或應工程師或工程師代表、或任何正式成立的工程管理處的要求，承包人必須自費提供和維護與工程有關的所有燈光、警衛、柵欄和看護以保衛工程，或保障公眾及其他人的安全和便利。
20．（1）from the commencement of the works until the date stated in the certificate of completion for the whole of the works pursuant to clause 48 hereof the contractor shall take full responsibility for the care thereof．provided that if the engineer shall issue a certificate of completion in respect of any part of the permanent works the contractor shall cease to be liable for the care of that part of the permanent works from the date stated in the certificate of completion in respect of that part and the responsibility for the care of that part shall pass to the employer． provided further that the contractor shall take full responsibility for the care of any outstanding work which he shall have undertaken to finish during the period of maintenance until such outstanding work is completed．in case any damage，loss or injury shall happen to the works，or to any part thereof，from any cause whatsoever，save and except the excepted risks as defined in subclause（2）of this clause，while the contractor shall be responsible for the care thereof the contractor shall，at his own cost，repair and make good the same，so that at completion the permanent works shall be in good order and condition and in conformity in every respect with the requirements of the contract and the engineer's instructions．in the event of any such damage loss or injury happening from any of the excepted risks，the contractor shall，if and to the extent required by the engineer and subject always to the provisions of clause 65 hereof， repair and make good the same as aforesaid at the cost of the employer．the contractor shall also be liable for any damage to the works occasioned by him in the course of any operations carried out by him for the purpose of completing any outstanding work or complying with his obligations under clauses 49 or 50 hereof．