
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given the function $f(x)=( \frac {1}{3})^{2x+k}$, if the graph of the function $f(x)$ passes through the point $(-1,3)$,
$(1)$ Find the value of $k$;  
$(2)$ If $f(a)\geqslant 27$, find the range of the real number $a$;  
$(3)$ If the function $y=f(|x|)-b$ has two zeros, find the range of the real number $b$.

Present the answer in LaTex format: \boxed{Your answer}
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