Your advisor is giving good advice. It is unlikely that anyone would consider such things to be plagiarism for a number of reasons. 

First, other than in exceptional cases, there isn't much "creativity" in the questions. The questions are not especially likely to capture the "thoughts and ideas" of the questionnaire writer. 

Second, and related to the first, is that there are a limited number of ways to say such things. 

Thus, questionnaires of this kind tend to be very similar.

Watch out for exceptional cases (the creativity issue), but in the main, there should be no issues.