She is a(n) 1 girl.2 name is Lingling.She is a(n) 1 girl.2 name is Lingling.3 is thirteen years now.She's 4 No.10 Middle school.She is in 5 .She has a good friend at school.He's name is Jim.He is 6 American boy.7 eleven.He is in No.3 Middle school,8 .Mrs Zhang is 9 English teacher.She is a 10 teacher( )1.A Chinese B English C American D Japanese ( )2.A His B She's C He's D Her ( )3.A He B She C We D I ( )4.A on B / C a D in ( )5.A Class Two,grade one

问题描述:

She is a(n) 1 girl.2 name is Lingling.
She is a(n) 1 girl.2 name is Lingling.3 is thirteen years now.She's 4 No.10 Middle school.She is in 5 .She has a good friend at school.He's name is Jim.He is 6 American boy.7 eleven.He is in No.3 Middle school,8 .Mrs Zhang is 9 English teacher.She is a 10 teacher
( )1.A Chinese B English C American D Japanese
( )2.A His B She's C He's D Her
( )3.A He B She C We D I
( )4.A on B / C a D in
( )5.A Class Two,grade one B Grade One,Class Two
C Class Two,Grade One D grade one,class two
( )6.A a B an C / D the
( )7.A His B Her C He's D She's
( )8.A too B and C teacher D student
( )9.A their B they C my D your
( )10.A very B very good C right D old

ADBDCBCAAB,亲,把最佳答案给我吧!

ADBDC BCAAC

She is a(n) 1 girl. 2 name is Lingling. 3 is thirteen years now. She's 4 No.10 Middle school. She is in 5 . She has a good friend at school. He's name is Jim. He is 6 American boy. 7 elev...

1/3 = 1/(1*3) = 0.5* (1/1 - 1/3)
1/15 = 1/ (3*5) = 0.5 * (1/3 - 1/5)
……
加起来就是0.5*(1/1 - 1/3 + 1/3 - 1/5 + …… + 1/11 - 1/13) = 0.5 * (1 - 1/13) = 6/13