a lack of的用法和样例：
- The main impediment to growth was a lack of capital.
- Stress and tiredness often result in a lack of concentration.
- Her decision seems to show a lack of political judgment.
- Her decision seems to show a lack of political judgement.
- If air weren't admitted into the bell jar, the electric bell in the bell jar would not ring because of a lack of a medium.
- Dejected because of a lack of companionship.
a lack of的相关资料：