某种型号的电子管的寿命X(以小时计)具有以下的概率密度%

This pair of socks 8 yuan A.is B.are C.do D.have 我和朋友一起学英语口语,请问口语好的朋友对于学口语有什么好的意见吗? 北京最近总下雨啊,什么时候能晴. 最近老是下雨,啥时候晴啊? 这几天怎么老是下雨啊,什么时候天气会晴啊,郁闷 这几天还会下雨吗=-O什么时候才晴啊? 已经晴了一个月了,什么时候会下雨呢 英语somebody和somebody else有什么区别 请用简短的话概括短文《丰碑》主要讲了一件什么事?一定要自己写的呦~ 皮皮鲁和活车中的好词好句有那些 我国的地势特征是怎样的?这种特点决定了我国的主要河流走向是怎样的? the problem is ___difficult for us ____.A so work outB very too to be worked outC rather too to work outD quite too to work it out I feel in love with you .Do you believe Difficult as the problem of pollution is_______,no one should just stop tryingA.to solve B.to be solve Csolving Dbeing solved I wouldn't wanna be anybody else.是什么意思 I would not wanna be anybody else~ she always feels _ _ when she has an important exam怎么填,汉语意思是她有重大考试的时候总是感到紧张 英语连词成求解句 求解连词成句,英语 are what doing for you the national day coming连词成句 英语,连词成句 Big things are coming!最好的中文解释 you are so sweet to remember my big day. Verify that the file is not write-protected and try again.谁知道 How long are you ____ from school?Only a few days.I'm coming back soon.A.getting B.going C.coming D.away 英国为什么被称为“英伦三岛”? 英国为何又称为“英伦三岛”“英伦”中的“伦”是何意？ 英国何时统一了英伦三岛 what do you think of the matter?What do you think of the matter?This is a matter of ____ importance,I think.A.especial B.fairly C.rather D.special请问A和D有何区别? 翻译:what's matter with you noting,just sadiy .dear,do you remember tha 英语连词成句求解 He didn't agree with me at first,but I___persuade him to sigh the agreement later.A.could B.might C.should D.was able to 求答案和句子意思