Double Trouble

The actual title of Monday's Brain Bender from the handy dandy discount MENSA calendar...

Ready to play?

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Fill in each blank below with a word that fits the definition on the left when read normally and fits the definition on the right when read backwards.

• To fight _______ Knocks
• Frost ________ A ruler
• Put forth ________ The fourth dimension

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So, okay! You know what to do... The answers will be found later in the comments. See you then!

Update: Both Teresa from Technicalities and jvh from Showcase of a Shattered Mind are Smartypants. Whoohoo!