Our usual terms of payment are by confirmed, irrevocable L/C payable by sight draft ______ presentation of shipping documents.

A．among

B．between

C．about

D．against

波形梁护栏验收时，立柱定位正确，埋置深度满足设计要求，立柱周围回填土密实，人力不应摇动立柱。