团队中缺乏积极性，需要解决。

In the team, motivation ___is ___lacking and needs to be addressed.

危机期间缺乏真正的领导力。

True leadership ___was ___lacking during the crisis.

有时，当我们最需要时，却缺乏最简单的解决方案。

Sometimes, the simplest solutions ___are ___lacking when we need them most.