5: Arrow stopper, perhaps
9: Palindromic preposition
12: Emulate a couch potato
19: Whistle-blowers, of a sort
24: 'I'm Sorry' singer Brenda
25: Casting director's assignments
26: Black-and-white divers
27: Analyze in English class
28: Tests that allow talking
37: Cul-de-___ (dead end roads)
42: '___ me think about it'
45: Narrow margin of victory
46: '__ Resartus' (Carlyle)
48: Something that might make the fur fly?
50: Merrill Lynch's bull, e.g.
55: Frequent Las Vegas money taker