阅读下面的短文，根据短文后的要求答题

Ourworldisfullofsignsandsymbols.Mostofthetimewedon’treallyneedtothinkaboutthem.Goodexamplesofthese“invisible”symbolsaretheonesusedfor“Play”“FastForward”and“Rewind”.WefindthemoneverythingfromoldtapeplayerstoDVDplayersremotecontrolsandcomputerkeyboards.Theyaresofamiliarthatwedon’treallyneedtopayattentiontothemanymore.Wecertainlyneverthinkaboutwhofirstdesignedthemorwhen.

Amorerecentbutincreasinglyfamiliarkindofsymbolisthe“emoticon”sometimescalledthe“smiley”.Youmightnotbefamiliarwiththenamesbutyou’vecertainlyseenthemmanytimes.Hereforexampleistheemoticonforhappy::-)Thisistheoneforsad::-(“Emoticon”isacombinationoftwowords“emotion”and“icon”.Aniconwasoriginallyareligiouspicturebuthasnowmorecommonlycometomeanasymbolusedonthecomputer.Emoticonsareusedtoshowfeelingsthatareoftendifficulttoexpresswhenwritinganemailorsendingatextmessage.

ModernemoticonsarethoughttohavebeeninventedbyacomputerscientistcalledScottFahlmanin1982.Hegotsotiredofpeoplethinkingthathewasseriouswhenhewasjokingthathesuggestedmarkingalljokeslikethis::-).Theideatookoff rapidlyandastheInternetbecamemorepopularsodidemoticons.Theoriginaltwoorthreehavenowbecomehundredscollectedin“dictionaries”oronwebsites.Andalthoughmostemoticonsstilltrytoimitateanexpressionofthehumanfacesomelike/o(amanscratchingheadmeaningconfusion)oro/(amanwavinggoodbye)showanaction.

101.WhydoestheauthorrefertothesymbolsonDVDplayersas“invisible”?(Nomorethan16words)

_________________________________________________________________

102.Explaintheunderlinedphrase“tookoff”inEnglish.(Nomorethan5words)

_________________________________________________________________

103.WhatmadeScottFahlmaninventthefirstemoticon?(Nomorethan10words)

__________________________________________________________________

104.Accordingtotheauthorhowdoemoticonsshowfeelings?(Nomorethan15words)

________________________________________________________________