His average high marks for each subject were followed by the notation, "Could do much better" or "Lacks concentration. "
He towers above most of his opponents, in inches and talent, but sometimes he seems to lack concentration.
As a night-owl who has difficulty waking up early, I was tired and lacked concentration on the journey to work.
He felt tired, lacked concentration and was short-tempered.
We didn't look tired in the first half, but we lacked concentration.
According to my friend, the child was a misfit in school; he lacked concentration and was not interested in anything.
Of the five members, Sae has the greatest amount of power to utilize, but lacks the training and concentration to fully tap into this potential.
The Federal Bureau of Investigation's initial inquiry lacked concentration and resources.
The training sessions went correct, but during the World Championship he lacked concentration and ended up in 26th position.
When Jillian worked with Nikki one-on-one, she still lacked motivation and concentration.