pressure n. 1.壓;按;擠;榨。 2.【物理學(xué)】壓力,壓強(qiáng);大 ...
absence n. 1.不在,缺席,缺勤 (opp. presence)。 2.缺乏,缺少,無。 3.心不在焉,不注意。 absencefrom (school, office) 缺(課),缺(席),缺(工),缺(勤),不在。 absence in (London) 暫離某地而在(倫敦)。 absence of mind 心不在焉,心神不定。 absence of reason 發(fā)狂。 in sb.'s absence 當(dāng)某人不在時,背地里。 in the absence of 無…時,缺少…時。 leave of absence 請假,準(zhǔn)假。 absence without leave 擅離職守。
Vacuum may be thought of as the absence of pressure . it is the measure of negative pressure between standardized atmospheric pressure and a theoretically perfect vacuum 真空可以被認(rèn)為缺少壓力。真空是以標(biāo)準(zhǔn)大氣壓的負(fù)壓和理論完全真空來測量的。