A.1+83 B.1+81 C.1+79 D.1+77
[单选题]1+1,2+3,3+5,1+7,2+9,3+11,1+13,…第40项为( )A.1+83 B.1+81 C.1+79 D.1+77
[单选题]1/5,1/3,3/7,1/2,( )A.5/9B.1/6C.6D.3/5
[单选题]:2/3,1/2,2/5,1/3,2/7,( )。A.1/4 B.1/6 C.2/11 D.2/9
[单选题]2/3,1/2,2/5,1/3,2/7,( )。A.1/4B.1/6C.2/11D.2/9
[单选题]1/2,1,2/3,3/4,5/7,()A.7/11B.8/11C.7/13D.8/13
[主观题]1/3,3/9,2/3,13/21,()A.17/27;B.17/26;C.19/27;D.19/28;
[单选题]1/3,3/9,2/3,13/21,()A .17/27B .17/26C .19/27D .19/28
[主观题]3,2,5/3,3/2,()A、1/2;B、1/4;C、5/7;D、7/3
[试题]3,2,5/3,3/2,()A、1/2;B、7/5;C、1/4;D、7/3
[单选题]:1/2,2/3,2/5,1/2,8/13,()。A.32/21 B.7/15 C. 9/11 D. 1