“S”后边的清辅音发音问题

“S”后边的清辅音发音问题
“S”后边的清辅音什么时候要改发为浊辅音吖
是不是全部都要吖~
我们6月20号考英语了哦~

字母s的读音有/s/、/z/、/M/、/{/这几种,下面主要讲讲发/s/音的几条规则.
一、s在词首时,除了sugar,sure以及sh组合发/M/以外,其余一般发/s/.
例：surface/'s+：fis/,serve/s+：v/,seven/sevn/,six/siks/,some/s)m/,sign/sain/
比较：design/di'zain/
一般前缀,合成词不影响其读音.s仍读成/s/.
例：unsafe/)n'seif/,unsatisfactory/)n$+tis'f$k+t+t+ri/,roadside/'r+udsaid/,teaspoon/'ti：spu：n/,snowstorm/'sn+ust&：m/
二、两个s在词尾时读作/s/.
例：grass,glass,address,press,success,pass,miss,stress,across,swiss,puss,progress,process,kiss
三、词尾s在u后读作/s/.
例：bus/b)s/,us/)s/,minus/'main+s/,abacus/'$bks/,plus/pl)s/,status/'steit+s/,virus/'vai+r+s/
四、在sis组合的弱读中,两个s都读作/s/.
例：emphasis/'emf+sis/,analysis+='nlsis/,thesis/'I：sis/,crisis/'kraisis/
五、s在字母c前常读作/s/.
例：muscle/'m)sl/,discipline/'disiplin/,science/'sai+ns/
六、s在某些前后缀中读作/s/.
1．在前缀mis-,dis-中,s读作/s/.
例：mismanage/?mis'm$niDN/,misjudge/?mis'DN)DN/,misbelieve/?misbi'l：v/,disorder/di's&：d+/,disobey/dis+'dei/
2．在后缀－sive,sity,－self,-some,-sy中,s读作/s/.
例：expensive/ik'spensiv/,intensive/in'tensiv/,decisive/di'saisiv/
yourself/j&：'self/,handsome/'h$ns+m/,troublesome/'tr)blsm/,tiresome/tai+s+m/,quarrelsome/'kw&r+ls+m/
七、s在清辅音前后常读作/s/.
1．s在清辅音前常读作/s/.
例：honest/'&：nist/,newspaper/'nj(：speip/,task/t%：sk/,satisfy/'s$tisfai/,grasp/gr%：sp/
2．s在清辅音后常读作/s/.
例：sportsman/'sp&：tsmn/,works/w+：ks/,stops/st&ps/,roofs/r(：fs/．
八、词尾se在字母r,l,n后读作/s/.
例：horse/h&：s/,nurse/n+：s/,worse/w+：s/,course/k&：s/,universe/'j(：nivs/,pulse/p)ls/,else/els/,tense/tens/,sense/sens/