-- Would you please show me your new radio?
-- I'm sorry. I ____ (listen) to the music. I didn't catch you.
— Sorry, I _________.
下列对分子、原子、离子的认识,正确的是( )
如图,直线AB,CD,EF相交于点O,且AB⊥CD,∠1与∠2的关系是____ .