Especially since he was going to need intense concentration and a very steady hand for the next few hours.

Why is it supposed that speaking comes naturally and needs no effort or concentration?

The next part is a little tedious, and I need complete concentration.

A revolution in science - profound things that need concentration.

Whatever she was doing, it obviously needed enormous effort and intense concentration.

You need concentration to show that you're in the city and not in the country.

"Which is why you need such concentration and cannot work all day?"

To meet these standards the worker needs total concentration and freedom from time pressure.

Right now, he needed their cool heads, concentration, and unquestioned genius.

"You need such discipline and concentration to do a book."