不足：未达到指定数量或水平的失败；短缺。
缺口：供应量与期望、需求之间的差额。
shortfall /ˈʃɔːtˌfɔːl/ TEM8
可数名词 If there is a shortfall in something, there is less of it than you need. 不足
The government has refused to make up a $30,000 shortfall in funding.
政府已经拒绝补足3万美元的资金短缺。
差额-引用次数：1
赤字-引用次数：1
参考来源南京国民政府初期的安徽财政整顿
不足之数
... cross-dressing 伪娘（穿着异性服装） short fall 亏空，缺少 breakdown 故障 ...
... sharp fall急剧下降 short fall不大的差距 steady fall稳定地下落 ...
亏空；缺少
Although rain means rain sway, not only round, but every raindrop, after all, only a short fall, I now see rain, has been different from the previous one second.
虽然雨意绵绵荡荡，无止无休，然而每一滴雨珠毕竟只有一次短暂的坠落，我此刻所见雨丝，已与前一秒钟不同。
The rapid acceleration-deceleration forces of violent shaking can cause much more damage to brain tissue and blood vessels than a direct bump to the head caused by a short fall.
猛烈摇晃时，迅猛加快—减慢产生的力量给脑组织和血管带来的损害可能比突然跌落直接撞击头部要严重得多。
The sea may rise or the land may fall; either way the sand dunes will be gone in a short time.
海平面可能会升高，或者陆地可能会下降；不论发生哪种情况，沙丘都将很快消失。
The pledges announced by NATO Secretary-General Anders Fogh Rassmussen fall short of the 10,000 additional troops that Pentagon officials hoped for.
VOA : standard.2009.12.05
Because very often,with very good intentions, we may fall short of what we are capable of doing, or in some situations,even hurt more than help.
因为很多时候，即使有很好的意愿，我们的能力还是有限，或在某些情况下，我们带来的伤害多于帮助。
幸福课课程节选 : 哈佛公开课
In other words, set your sights high, knowing you will probably fall short.
换句话说即将目光放远，了解到你可能将会失败。
政治哲学导论课程节选 : 耶鲁公开课
Jiang says the funds pledged by developed nations so far still fall short of what developing countries expected.
VOA : standard.2009.12.16
But some say his efforts fall short of addressing the real problem.
VOA : standard.2009.10.15
Based upon WD and Seagate discussions in their quarterly conference calls last week calendar Q4 2011 will probably see a short fall of 20-40 million HDDs compared to demand of 170-175 million drives total.
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They will still fall short, though, because they are supposed to fall short.
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It is likely that higher prices will result from the flood induced production short-fall.
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