不是的，比如这个单词
offence 读音是
[ə'fens]
望采纳，谢谢
另外拓展一下。O的发音规则
O的发音规律
O字母在非重读音节中的发音规则
O及其所有的字母组合如or,ow,oa在非重读音节中常发/ə/,/əu/
/ə/:recognize,command,official,elevator,secondly,concern,vocabulary,violence, opinion,Terror,stubborn,ivory,dragon,decorate,sailor,compete,competor,mascot,operator,technology,revolution,personal,protection,mosquito,contain,dinosaur,actor,humorous ,petrol.
/əu/: pillow. mosquito,motto.
O字母及o字母组合在重读音节中的发音规则。
一．O字母在重读音节中的读音规则
（1）o在重读开音节中读作/əu/：
devote,overcoat,hopeful,vote,mobile,local,explode,homeland,host,hopeless,total,programmer,zone,antelope,olive,glory. (2)o在重读闭音节中读作/ɔ/：
Lorry,block,fond,shock,conquer,responsibility,motto,goddess,operator,logical,technology,solve,rocket,mop,electronic,loss,respond,confident. 注：在-r音节中读作/ ɔ:/
Ignore,northwestern,singapore,transport,shortcoming,organize,report,former,informal,explore,supporting,importance. 注：当o+m,n,v,th时，o常读作/ʌ/ Recover,honey
二．o字母组合在重读音节中的发音规则
oa常读作/əu/:
overcoat,goal,download,coach. Oi,oy常读作/ɔi/:
Boil,voyage,destroy,android,spoil,employ,form,perform oo常读作/ u:/: loose,troop,foolish ou常读作/ au/:
outdoors,found,outline,doubt
ow常读作/ au/或/əu/:
power,flow,nowadays,anyhow,download,powerfu
望采纳，谢谢哦
