他每个月都会为社区项目贡献一些时间。

He ___contributes some time to the community project every month.

她每月为这本科学杂志撰写专栏文章。

She ___contributes a monthly column to this science magazine.

公司每年向当地学校捐赠电脑。

The company ___contributes computers to local schools every year.

过度使用塑料制品导致了环境污染问题。

Excessive use of plastic ___contributes to environmental pollution problems.