这条河在雨季时会变宽。

The river ___widens during the rainy season.

学校正在扩大课外活动的种类以丰富学生的选择。

The school is ___widening the variety of extracurricular activities to enrich students' options.

教育资源的差距正在扩大。

The gap in educational resources is ___widening.