混凝土由实验室配合比根据现场砂石含水率调整后的配合比称为（ ）。

A. validation
B. implementation
C. maintenance
D. testing occurs during each phase.

A. The pressures to deliver the product on time are such that postponed documentation may never be delivered.
B. The individual responsible for an early phase may not be available by the time that the documentation needs to be produced.
C. A product is constantly changing during development. Until the changes are documented, modifications will be difficult to achieve.
D. Postponed documentation may never be delivered, the individual responsible may have left later in the project and the fact that the product is constantly changing are all reasons why each phase should be fully documented before the next phase begins.