The cement casing around the nuclear reactor is at risk.核反应堆外面的水泥防护罩处于危险之中。

a phone with a brushed aluminium casing配有拉丝铝壳的电话

the outer casings of missiles导弹的外壳

100 per cent recyclable aluminium casing可100%回收利用的铝壳材料

The plastic was necessary because cardboard casing did not have the required strength.塑料是必须的, 因为硬纸板外壳材料达不到强度要求。