地图上的红色标记表示重要地点。

The red symbols on the map ___denote important locations.

字母'X'在这个方程式中表示未知数。

The letter 'X' ___denotes an unknown value in this equation.

他皱起的眉头表明他很不高兴。

His furrowed brow was ___indicating his displeasure.