缺额的英文：
shortage
vacancy

参考例句：

A shortage of 50 tons
五十吨的短缺额

shortage是什么意思：
n. 不足，短缺；缺少量；不足额；缺点

There is a shortage of principal.
资金有些短缺。

There's an acute shortage of rain.
这里严重缺雨。

This area has an acute shortage of water.
这个地方缺水严重。

You must improve your shortage.
你必须改进你的缺点。

There's an acute shortage of rain.
这里严重缺雨。

vacancy是什么意思：
n. 空缺，空位，空白；空虚

There are a few vacancies on the second floor.
在二楼有几个空房间。

We have a vacancy for a computer programmer.
我们有一个电脑编程师空缺。

The traveller searched in vain for a vacancy at motels.
旅行者无法在汽车旅馆找到空房间。

I wonder if you have any vacancies for three nights.
不知你们有没有住三天的空房间。

His resignation left a vacancy on the board of directors.
他的辞职给董事会留下了一个空缺。