Today some people call Amsterdam the “City of Bicycles”____ the convenience for bicycles there.

A．while

B．before

C．because

D．because of

简要说明抽查法、审阅法、核对法、盘点法、函证法、观察法和鉴定法各自的涵义、适用范围，以及实施时各自应注意的问题。