孙炳荣回答:
鲁班走路被一种锯齿的草割伤,仔细观察发明了锯
an=3n-2,数列bn=2^n-1,令集合A={a1,a2,a3...an,...},bn={b1,b2,b3.bn…},an=3n-2,已知数列{bn}的通项公式是bn=2^n-1,集合A={a1,a2…an…},B={b1,b2…bn…},将集合AB中的元素按从小到大的顺序排成一个新的数
thereis____"f"inthewordknife,butitmakes___/f/sound.A,a;anB,an;aC,an;anD,a;awhosetrousersarethese?___,Ithink.A,theyB,theirC,theirsD,themGongQiuyanthought___quite___tolearnEnglishwell.A,it's;easyB,it,easilyC,it's;easilyD,it