key feature的用法和樣例：
例句
- At best, one can outline a few key characteristics.
充其量你只能大致描繪出它的一些關(guān)鍵特征。 - Another key feature of this remnant is the long white line running from left to right across the center called the equatorial belt.
該遺跡的另一關(guān)鍵特征是，赤道方向有一道明亮的白色環(huán)帶，自左向右穿過(guò)穿過(guò)遺跡的中心，名為環(huán)赤道帶。
