4.翻譯:過去2小時的氣壓計變化為30毫巴。
(A)Hexametric change is 30 millibars within the last 2 hours.
(B)Barometric change is 30 millibars within the last 2 hours.
(C)Chronometric change is 30 millibars within the last 2 hours.
(D)Thermometric change is 30 millibars within the last 2 hours.