### Clue: Greenhorns try what 20 competitor does (8)
### Answer: GOSLINGS 
 ### Explanation: Definition: Greenhorns
 GO(an attempt;a try at a game, as in "go ahead, have a go") + SLINGS{what the hammer(answer to 20across) thrower does}.
Answer: Young inexperienced persons. If they don't learn, then they'll grow up to be geese.
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