The road construction is based on the agreement, one of _______ purposes is to ensure its completion on time.

A．which

B．whose

C．that

D．what

离码头采用尾先离；首倒缆的要求哪项不正确：（）

A.首倒缆应选强度大、质量好的钢丝缆

B.首倒缆应带至远离码头边的缆桩上

C.甩尾操作时，应用微进或慢进，并注意不使其受顿力

D.应有足够的长度，减少其所受张力