Thelastsentencemeansthataknowledgeoffishsoundscanhelpmanto______.
A.avoidconfusioninfishingactivity
B.avoidunneededeffortinfishsoundstudies
C.detectenemysubmarines
D.pickupnewsounds
正确答案：C答案为C。根据第二段第三句及最后一句，Hecanalsoapplythisinformationtothemoreeffectiveutilizationofthelisteningspotshehassetuptodetectenemysubmarines...andthesoundsentr ymustd ecidewhetherornottocallanalarm作出该项选择。
