furrow|furrowed|furrowing

他思考时，眉头间出现了一条深深的皱纹。

A deep ___furrow appeared between his brows as he pondered.

他的额头微微皱起。

His forehead is slightly ___furrowed.

他皱着眉头读那份复杂的报告。

He was ___furrowing his brow while reading the complicated report.