It means released. The laughter wanted out; so he released it. :)1.Hugh let out a whoop of laughter.
Q1: What does "let out" mean here? thanks^^
The repetition of not serves to emphasize the first part of the statement. It could be said as You can't risk it with the championships so close, but the way it is said in the example sentence is perhaps a little more emphatic.2.You can't risk it, not with the championships so close.
Q2: Why it should have been use 'not' after the comma?
If you have hooked a fish that means you have caught it. If you have your hooks into somebody that means that person has fallen for you (is attracted to you).3.Have you got your hooks into John Powell yet ?
Q3: What's 'hook' stand for ? thanks^^