Hi Valeriy,
Open the survey in CRM_SURVEY_SUITE and then right click on it.
Select the option View Source which will open the HTML Content of the survey.
Scroll down towards bottom where <BODY> tag starts.
Below is my example survey from where I picked up Section 1.
<body onLoad="hideFields()">
<div class="Title">This is a Test Survey</div>
<form action="SAPEVENT:WFF_EVENT" class="saveSnapshot" enctype="" id="SAPSurvey" method="post" onSubmit="return check(this)">
<input name="svyApplicationId" type="hidden" value="CRM_SURVEY_CORE">
<input name="SurveyId" type="hidden" value="ZTEST">
<input name="svySurveyId" type="hidden" value="ZTEST">
<input name="svyVersion" type="hidden" value="0000000003">
<input name="SchemaVersion" type="hidden" value="1 ">
<input name="svySchemaVersion" type="hidden" value="1 ">
<input name="svyLanguage" type="hidden" value="EN">
<input name="conid" type="hidden" value="">
<input name="svyMandatoryMessage" type="hidden" value="Fill all mandatory fields before saving">
<div Id="" class="Section1">
<div class="SectionText1">Section 1</div>
<div Id="q1" class="Question">
<div class="QuestionText">Question 1</div>
<table datatable="0" summary="Survey Questions" class="QuestionListInline">
<tr>
<td class="ListAnswerFieldText">Maintain Answer and Attributes</td>
<td class="ListAnswerField">
<input class="AnswerFieldRW" maxlength="40 " name="survey/result/q1/a1" size="40 " type="text" value="">
</td>
</tr>
</table>
</div>
<div class="Event">
<input name="onInputProcessing(SUBMIT)" type="hidden">
<input class="ButtonInside" type="submit" value="Save">
<input class="ButtonInside" type="reset" value="Reset">
</div>
</div>
<div Id="" class="Section1">
<div class="SectionText1">Section 2</div>
<div Id="q2" class="Question">
<div class="QuestionText">Question 2</div>
<table datatable="0" summary="Survey Questions" class="QuestionList">
<tbody>
<tr>
<td class="ListAnswerField">
<input class="AnswerFieldRW" maxlength="20 " name="survey/result/q2/id_0050568e5ac81ed59fa7278b4fff63a2" size="20 " type="text" value="">
</td>
<td class="ListAnswerFieldText">Answer for Question 2</td>
</tr>
</tbody>
</table>
</div>
</div>
</form>
</body>
check the names for your class. Also you can try with the class name "Question" but then script will be different to find the parent section of the question and hide it.
Give a try.
Regards,
Naresh