could you make some posters for me __ you are there?是添while还是when

题目

could you make some posters for me __ you are there?是添while还是when
答案是选while

答案

强调主句的动作在从句动作的发生的过程中用while
整句翻译：当你在那时,能不能帮我做一些海报?