Only if it is necessary for the cause in question then it is clearly contributing to the effect.

Although migraines appear to run in families, environmental factors clearly contribute to the onset of an episode.

Plastic packaging clearly contributes enormously to our quality of life.

The rent tax, I might point out, clearly contributes to the city's reluctance to control commercial rents.

But they clearly contributed to a massive 18-car pileup earlier in the race.

The state of obesity clearly contributes to insulin resistance, which in turn can cause type 2 diabetes.

"It's clearly contributing to the rising costs of prescription drugs and health care."

The European policy that we want must clearly contribute to greater freedom and openness.

The new directive will clearly contribute towards the clarification and better understanding of the extensive current legal arrangements in this area.

But it's very clearly contributed to keeping the town a lot healthier than others like it.