The new strains are less efficient, more prone to mould and pests, and require more intensive effort for lower yield.

Clothes sales have turned positive in recent months after an intensive effort to make its womenswear more fashionable.

A century and more had to pass before the fruits of this intensive effort were fully ripened.

For into the planning of the organization, training, and equipment of this unit was poured the accumulated experience of four years' intensive effort.

After about six weeks of intensive effort, they finally concluded that they were getting exactly nowhere.