长时间使用这把刀切硬物会使其变钝。

Cutting hard objects with this knife for too long will start ___blunting its edge.

时间慢慢冲淡了失去亲人的痛苦。

Time is gradually ___blunting the pain of losing a loved one.

长时间盯着屏幕会钝化你的专注力。

Staring at screens for too long is ___blunting your ability to focus.