unmarked expression的用法和樣例：
例句
- Reports say the hikers ignored warnings and straightly crossed the unmarked border between northern Iraq and Iran.
報告稱(chēng)這些旅客不顧警告直接穿越伊拉克北部和伊朗無(wú)標記的邊境。 - The driver of any vehicle shall yield the right of way to a pedestrian on any portion of any unpaved road or crossing within any marked or unmarked crosswalk of a paved road.
任何交通工具的駕駛員將把右側讓給在沒(méi)有鋪石磚的道路任何一部分，或在鋪設道路有標記的或無(wú)標記的人行橫道以?xún)鹊男腥恕?/li>
