No difficulties occur in what has never been tried.

But difficulties can occur when parents view their child as physically fragile even after a medical problem is under control or no longer a concern.

Officials at the magazine have said that they believe any difficulties are occurring outside the editorial offices.

Here a new difficulty occurred, which nearly ended in a serious quarrel.

Breathing difficulties may occur but more commonly are found in children.

Other difficulties occur when the woman doesn't have what she feels like eating and the child suffers.

A difficulty, however, occurred in the course of the work, which had neither been foreseen nor provided against.

The most persistent difficulty occurred whenever her mother fed the baby.

If severe difficulty breathing occurs, immediate medical attention is needed.

It may also be observed from (15.10) that difficulties occur at the points.