单项选择题
A.a lock that is open
B.a sunken barge
C.a dolphin，water intake and discharge
D.the end of a wharf
单项选择题 As you approach mile 427.6 AHP，you see on the right side a white buoy with orange bands and diamond. This buoy marks（）.
单项选择题 As you approach Giles Bend Cutoff Light (mile 367.7 LDB)，what type of daymark would you see on the light structure?（）
单项选择题 As the temperature of the air reaches the dew point，（）.