—Have you ever been to Washington?

---Yes, ____shall I forget ___ it for the first time.

A．however; visiting

B．never;visiting

C．never;to visit

D．forever; to have visited

同车道行驶的机动车后车应（）

A、根据行驶速度，天气、路面情况，同前车保持必要的安全距离

B、与前车保持不小于30米的距离

C、与前车保持不小于50米的距离