sign如何发音?是不是读作萨in

sign如何发音?是不是读作萨in sign in sign怎么发音 check in 和sign up是不是一个意思? sign in to yahoo? sign in 和 sign up 的区别 sign-in and sign-out是什么意思 sign in 与 sign out 怎么翻译? 这句话是不是少了一个that is?We sign in Facebook not very easy .应该是we sign in facebook that is not very easy是吗 要个英文名,发音同 sign . 英语定冠词与不定冠词用法中,如何知道一个名词是不是特指?例如：A smile is ___ strong sign of friend.sign不是特指？ ERROR SIGN IN PID,PLEASE SIGN IN ON CORRECT PID PLEASE SIGN IN FIRST.小写是：please sign in first. sign in to facebook是什么意思 sign in to facebook是什么意思 not-in-use-sign是什么意思 sign up和sign in二者有何区别? 关于ghrelin,是哪国的单词?如何发音?是不是德语?