v.(使)变硬,(使)强硬( stiffen的第三人称单数 );
例句:
Heating the foam stiffens it and forms it.
暖气泡沫stiffens它和形式.
The road stiffens after rain.
雨后的道路变得十分难走.
Mud stiffens when it dries.
泥巴一千就变硬.