
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 line $l: y=kx+4$ and the ellipse $C: \frac {x^{2}}{5}+y^{2}=1$,
(I) If line $l$ passes through the left focus of $C$, find the value of the real number $k$.
(II) If line $l$ has common points with ellipse $C$, determine the range of values for the real number $k$.

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