The tree are green in spring.
A:flower
B:leaves
C:leaf
Do you want over. We can play some games.
函数y=2sin2x+π2是( )
苯甲酸(C6H5COOH)可用作食品防腐剂,其酸性比醋酸强。下列对苯甲酸性质的推测不合理是( )