【正确答案】正确答案：What all this superficial engagement means for us developmentally．
【答案解析】解析：根据题目中Sherry Turkle和worry定位到第3段第3句。题目中的worry most是用了动词形式来同义表达原文该句中的the biggest worry，故答案为该句的表语从句，即What all this superficial engagement means for us developmentally。
问答题
How will one feel when he gets a shot of dopamine according to the passage?
【正确答案】正确答案：Happy．
【答案解析】解析：根据题目中的gets a shot of dopamine定位到第4段最后两句，该短语出现在该段倒数第2句，而最后一句中的put it simply表明其后学生讲述的内容是对上一句Turkle的话的通俗解释。故可推断get a little shot of dopamine意味着start to have some happy feelings。可见答案为Happy。