– “Where is Dung?” – “He is work. He is busy his monthly report. A. on/for B. in/about C. to/through D. at/withĐoạn văn7/40– “Where is Dung?” – “He is ___ work. He is busy ___ his monthly report.on/forin/aboutto/throughat/withGiải thíchĐáp án: D