孩子们不愿做作业却愿意花太多时间在社交媒体上，家长为此感到很担心。当下这种情况很普遍。(it)

Nowadays, it is common that kids are willing to spend much time on social media instead of doing homework, which makes parents very worried.

考查固定句型，主语从句，固定短语，时态，定语从句和主谓一致。“当下” 是nowadays，“某种情况很普遍” 是固定句型it is common that，其中it是形式主语，that引导主语从句，“孩子们” 是kids，“愿意做某事” 是be willing to do sth.，句子描述客观事实，时态用一般现在时，主语kids是复数，be动词用are，“花太多时间在……上” 是 “spend much time on ...”，“社交媒体” 是social media，“不愿做作业” 是instead of doing homework，“家长为此感到很担心” 用which引导的非限制性定语从句，which指代前面整个主句的内容，“家长为此感到很担心” 也就是 “这让家长很担心”，时态用一般现在时，翻译为 “which makes parents very worried”。故翻译为：“Nowadays, it is common that kids are willing to spend much time on social media instead of doing homework, which makes parents very worried.”。