The explanation for insensitivity to smell seems to be that brain finds it 14 to keep all smell receptors working all the time but can 15 new receptors if necessary.

• 对气味不敏感的解释，好像是由于大脑发现保持全部嗅觉感受器持续工作(14)效率不高，但如果必要的话可以(15)产生新的感受器。