A clock that has ticked in the same room for years is not heard at all until it stops. Yo nervous sys reports cha rather th steady condi, and sou that d not va are filt out wit minutes. Silence is itself a change, so the moment the ticking ends the absence arrives in full attention. The same habit explains why a smell fades soon after you enter a room and returns when you step outside.

Type only the missing letters. Each box is one letter, and the number of boxes matches the letters that are missing.