10-62. 10-63. 10-64. 10-65. On large ships, the goal of the CHT system  is  to  provide  the  capacity  to hold shipboard sewage generated over what  period  of  time? 10-66. 1. 24 hr 2. 12 hr 10-67. 3. 6 hr 4. 3 hr All  internal  surfaces  of  CHT  tanks  must be  coated  in  accordance  with  which  of the  following  publications? 1. Naval  Ships'  Technical  Manual, Ch 631 (9190) 2. Naval  Ships'  Technical  Manual, Ch 503 (9470) 3. NAVFAC  P-908 4. OPNAVINST   6240.3E Comminutor  and  aeration  systems  are  used with  ships  whose  holding  tanks' capacities  are  at  least 1. 1000    gal 2. 2000   gal 3. 3000   gal 4. 4000   gal A  high  level  alarm  sounds. What immediate  action  should  you  take  to prevent  flooding  of  the  spaces? 1. Close isolation valves on the upper and  the  lower  drains 2. Open  the  isolation  valves  on  the upper  and  the  lower  drains 3. Close  isolation  valves  on  drains below  the  overboard  discharge  and divert  the  upper  level  drains overboard 4. Open  isolation  valves  on  drains below  the  overboard  discharge  and divert  the  upper  level  drains overboard 10-68. Question  10-66  is  to  be  judged  True  or False. Exposure  to  continued  or  intermittent sounds  can  cause  loss  of  hearing. Loss  of  hearing  sensitivity  generally occurs  in  which  of  the  following  ranges? 1. 6,000   to    10,000    Hz 2. 4,000    to 6,000 Hz 3. 3,000    to 4,000 Hz 4. 500    to 3,000    Hz What  is  the  purpose  of conservation   program? the hearing 1. Identify  noise  sources 2. Reduce  exposure  of  personnel  to potentially   hazardous   noises 3. Test  the  hearing  of  noise-exposed personnel 4. Provide   hearing-conservation   devices Question  10-69  is  to  be  judged  True  or False. 10-69. All  personnel  who  are  exposed  to potentially  hazardous  noise  may  wear hearing  protection  devices  at  their  own discretion. 66