In the STEM fields, things change quickly. Having an engineer who is at least aware of current technology or the direction technology is going is much more valuable than one that only focuses on what they know and is not willing to look outside their own skillset to learn new things.
The question isn't really about what you use to stay current; it's more about the fact you make an attempt to stay current in the first place. An appropriate answer is anything that demonstrates that you try to keep your skillset updated, or at very least, are aware of changes in the engineering world. Some examples include online articles, virtual webinars, blogs, and community forums.
