单项选择题
A.above the polar circles
B.in a low pressure area
C.during periods of low temperatures
D.in the doldrums
单项选择题 The diurnal pressure variation is most noticeable in the（）.
单项选择题 The daily recurring pattern of pressure changes most noticeable in low latitudes is the （）.
单项选择题 That BE IT KNOWN THAT MV GLUCKAULF UNDER MY COMMAND HAS A DWC OF 12，431 M/T ON SUMMER LOADLINE，AND A BALE CAPACITY OF 18，439 CU.M.AND A GRAIN CAPACITY OF 19，941 CU.M.is likely to be the wording of（）.