How to insert records in Big Object through developer console?

I am creating Big Object through workbench like Survey__b. I inserting record through developer console, in this time showing error:

Variable does not exist.

But i have all variables in the big object. When i highlight these fields(Question1__c, Answer1__c,WhatID__c,WhatObject__c) inserting WhatTime__c only and get ID. How to insert all fields? could anybody help on this.

Inserting data:

Account a = [ select id, name from account limit 1 ];  
Survey__b survey = new Survey__b();  
survey.WhatID__c = a.id;  
survey.WhatTime__c = System.today() + 1;  
survey.WhatObject__c = 'Account';  
survey.Question1__c = 'What is the rating';  
survey.Answer1__c = '1';  
Database.SaveResult saveResult = database.insertImmediate(survey);  
System.debug( ' success ' + saveResult.isSuccess() + ' ' + saveResult );