Allergies are a main trigger for asthma attacks.

This is sometimes seen as one of the main trigger of the Khmelnytsky Uprising.

"The main trigger is that this is now an incredibly cheaper state," said a Republican official, speaking on condition of anonymity.

In the majority of cases the main trigger of landslides is heavy or prolonged rainfall.

If, within a few seconds, the main trigger is then pressed, a high power shot would be fired.

The writing-off, she said, was the main trigger for her final resignation.

These events were one of the main triggers for the Crimean War of 1856.

Ultraviolet (UV) radiation from the sun is the main trigger of these cancers, and people with fair skin are especially at risk.

The Arctic region is attracting more and more attention, due to the effects of climate change, the main trigger of developments.