Someday, he would come to understand the necessity of what she was doing.

I still don't understand the necessity of observing a 2 1/2-year-old almost a year before he is to enter.

He understood the unpleasant necessity of what she was doing.

But would they understand the necessity of what he did?

Understanding the necessity, the spell is cast and the army moved.

He was the only one who seemed to understand the necessity of what you want from them.

She understood the necessity, but we had to be careful.

And as we are killed, so the people will come to understand the necessity of the revolution.

I'm sure she'll understand the necessity for what we did.

You will understand, I hope, the painful necessity for this visit.