Most of us take life for granted. We know that one day we will die, but usually we 1 that day as far in the future. When we are in buoyant health, death is all but unimaginable. We seldom think of it. The days 2 out in an endless vista（远景）. So we go about our petty tasks, hardly aware of our 3 attitude toward life. The same lethargy（懒散）, I am afraid, characterizes the use of all our 4 and senses. Only the deaf appreciate hearing, only the blind realize the manifold blessings that 5 in sight. Particularly does this observation apply to those who have lost sight and hearing in life. But those who have never suffered impairment of sight or hearing seldom 6 the fullest use of these blessed faculties. Their eyes and ears take in all sights and sounds 7 , without concentration and with little appreciation. It is the same old story of not being 8 for what we have until we lose it, or not being conscious of health until we are ill. I have often thought it would be a 9 if each human being was blind and deaf for a few days at some time during his early life. Darkness would make him more 10 of sight; silence would teach him the joys of sound.