To elaborate on the answer to the first question, I'll select a reasonably close answer if there is one (which is most of the time), or otherwise skip it. On the second question, there wasn't a reasonably close one -- I usually pick the response that seems least likely to skew the data (which is sometimes skipping it, sometimes picking the "meaningless" answer).

And, yes, the fact that I answered "select the closest" to the first question, and then proceeded to not do that on the second, did strike me as ironic. But it was clearly the most accurate set of responses, so....