he prepared for great undertakings.
his labor did not require a great deal of skill.
Lexicographers drudge all day long.
She is driving away at her doctoral thesis.
She tugged for years to make a decent living.
She was digging away at her math homework.
she was in labor for six hours.
there is a shortage of skilled labor in this field.
We have to push a little to make the deadline!.