单选题 Most of the third-year students in our laboratory are occupied with experiments.
【正确答案】 C
【答案解析】该句意为：我们实验室的大部分研三学生在忙于实验。be occupied with：忙于；be bored with：对……烦了；be crazy about：对……痴迷，对……特别感兴趣；be busy with：忙于；be casual about：对……不在乎。