Somescientistssaythatanimalsintheoceansareincreasinglythreatenedbynoisepollutioncausedbyhumanbeings.
Thenoisethataffectsseacreaturescomesfromanumberofhumanactivities.Itiscausedmainlybyindustrialunderwaterexplosionsoceandrillingandshipengines.Suchnoisesareaddedtonaturalsounds.Thesesoundsincludethebreakingoficefieldsunderwaterearthquakesandsoundsmadebyanimalsthemselves.
Decibels(分贝)measuredinwateraredifferentfromthosemeasuredonland.Anoiseofonehundredandtwentydecibelsonlandcausespaintohumanears.Inwateradecibellevelofonehundredandninety-fivewouldhavethesameeffect.
Somescientistshavesuggestedsettinganoiselimitofonehundredandtwentydecibelsintheoceans.Theyhaveobservedthatnoisesatthatlevelcanfrightenandconfusewhales(鲸鱼).
AteamofAmericanandCanadianscientistsdiscoveredthatloudernoisescanseriouslyinjuresomeanimals.
Theresearchteamfoundthatpowerfulunderwaterexplosionswerecausingwhalesintheareatolosetheirhearing.Thisseriouslyaffectedthewhales'abilitytoexchangeinformationandfindtheirway.Someofthewhalesevendied.Theexplosionshadcausedtheirearstobleedandbecomeinfected(被感染的).
Manyresearcherswhoseworkdependsonoceansoundsareagainstalimitofonehundredandtwentydecibels.Theysaysuchalimitwouldmeananendtoimportantindustrialandscientificresearch.
Scientistsdonotknowhowmuchandwhatkindsofnoisesareharmfultooceananimals.Howevermanyscientistsdon’tthinkthatnoiseisagreaterdangerthantheybelieved.Theywanttopreventnoisesfromharmingcreaturesintheocean.
36.Accordingtothepassagewhichofthefollowingisincreasinglydangeroustoseacreatures?
A.Thesoundofcars.
B.Thesoundofvoices.
C.Man-madenoisepollution.
D.Thesoundofsteps.
37.AccordingtothepassagenaturalsoundsincludeallofthefollowingEXCEPT________.
A.soundsmadebyanimalsthemselves B.oceandrilling
C.underwaterearthquakes D.thebreakingoficefields
38.Whichofthefollowingisdiscus