lack of
英 [læk ɒv]   美 [læk əv]  
缺少；缺乏；需要

例句：
Lack of money is the main problem, as I see it. 

依我看，主要问题是缺钱。

Research has been constrained by a lack of funds. 

研究工作因经费不足而受限制。

The project had hung fire for several years for lack of funds. 

这个项目因缺少资金耽搁了好几年。

There is a lack of knowledge about the tax system. 

大家对税制缺乏了解。

We are very much aware of the lack of food supplies. 

我们完全了解食物供应的缺乏。

He pleaded family problems for his lack of concentration. 

他解释说注意力分散是因为有家庭问题。