语法与词汇 8._____in his study, he didn't know that all the others had left.(易错)
【正确答案】 B
【答案解析】be buried in one's study“专心致力于研究”，此处用其非谓语形式作原因状语。句意：他专心致力于研究，因此不知道其他人都走了。