英语单选第三题 only后都用 doing?

英语单选第三题 only后都用 doing? 英语单选第三题  第三题单选题英语怎么做 finish doing （单选） 高二英语单选题,第二题第三题为什么? 英语 一道选择填空题Mr Thompson was busy doing the experiment,only ___ 第三题单选题  中考英语单选：i was so angry at all ____he was doing ___i walked ou 英语单选：Usually Mike spends _____ time doing homework than Jack 一道英语单选Thinking that her daughter was doing homework,the moth 新概念英语第三册单词表 have a difficult time doing(单选