A:NaCl
B:Na2CO3
C:NaHCO3
D:NaOH
Which of the following can you see in the UK?
1
2
3
5
____
13
你是怎么想的?和小朋友说一说.
如图,已知直线AB和CD相交于O点,∠COE是直角,OF平分∠AOE,∠COF=34°,则∠BOD的大小为( )