A.經(jīng)度1′ B.緯度1′ C.經(jīng)度1″ D.緯度1″
A.31°29′48″N/121°30′30″E B.31°29′8″N/121°30′5″E C.31°29′20″N/121°30′43″E D.31°29′80″N/121°30′50″E
A.事故 B.險情 C.突發(fā)情況 D.異常情況