The point being the parking lot is the principal problem here.

关键是停车场是这里的主要问题。

The principal problem is that many people in the world still do not have resources to purchase or grow enough food.

世界上的很多人没有资源，无法购买以及种植粮食。

On just one morning this week I had three separate consultations with patients for whom loneliness was, at heart, the principal problem.

就在这周的一个早上，我对三名患者分别进行了咨询，他们的主要问题是孤独。

Most people think that the principal problem is that writers are too proud of what they have written.

大多数人认为主要问题是作家对他们所写的东西过于自豪。