听力原文：Are you aware that you actually possess six senses？ The sixth is a muscular sense

A、听力原文：Areyouawarethatyouactuallypossesssixsenses？Thesixthisamuscularsenseresponsiblefordirectingyourmusclesintelligently—totheexactextentnecessaryforeachactionyouperform.Forexample,whenyoureachforanobject,thesensorynerveslinkingthemusclestothebrainstopyourhandatthecorrectspot.Thisautomaticperceptionofthepositionofyourmusclesinrelationtotheobjectisyourmuscularsenseinaction.
B、Musclesarestringybundlesoffibersvaryingfromonefive-thousandthofaninchtoaboutthreeinches.Theyhavethreeuniquecharacteristics:theycanbecomeshorterandthicker;theycanstretch;andtheycanretracttotheiroriginalpositions.Underahighpoweredmicroscope,muscletissueisseenaslong,slendercellswithagrainytexturelikewood.
C、Morethanhalfofaperson'sbodyiscomposedofmusclefibers,mostofwhichareinvoluntary--inotherwords,workwithoutconsciousdirection.Thevoluntarymuscles,thosethatwemoveconsciouslytoperform.particularactions,numbermorethanfivehundred.Womenhaveonly60to70percentasmuchmuscleasmenfortheirbodymass.Thatiswhyanaveragewomancan'tliftasmuch,throwasfar,orhitashardasanaverageman.
D、(30)
A、Itmeansthatonealwaysknowswhathismusclesaredoing.
B、Itmeansthatoneperformssimpleactionswithoutworking.
C、Itmeansthatone'smusclesareusedonlytotheextentnecessaryforeachactiontheyperform.
D、Itmeansthatoneimprovesmuscularactionconsciously.