She is struggling to keep up with her schoolwork.
她在努力完成作业。
They were unable to keep up the instalments.
他们未能继续按时交付这笔分期付款。
Things are changing so fast, it's hard to keep up.
事情变化得太快了，很难跟上形势。
She did not bother to keep up with the news.
她不愿花时间去了解最新消息。