如图所示是自行车传动装置的示意图，若脚蹬匀速转一圈需要时间T，已数出链轮齿数为48，飞轮齿数为16，要知道在此情况下自行车前进的速度，还需要测量的物理量是_____________（填写该物理量的名称及符号）。用这些量表示自行车前进速度的表达式为v=___________________。

The project is not completed until （）.

A．the project scope is completed，administrative closure is completed and payment is received

B．formal acceptance is received，and any other requirements for project closure as stated in the contract are met

C．the customer is satisfied and final payment is received

D．lessons learned are completed