My sister has gone to work in Beijing， not for money， but herself．（ ）
A．improveB．improvedC．to improve
The 31st Olympic Games will be held in Brazil ______ August 5th，2016．（ ）
A．inB．onC．at
There are some ______in the garden．（ ）
A．potatoB．potatoesC．potatos
Could you please take ______notebooks to the teachers' office？（ ）
A．youB．yourC．yours
I often play ______chess after class．（ ）
A．aB．theC．/
Neither Li Hua nor I ___good at writing．（ ）
A．amB．isC．are