He was busy writing a story,only ( stopping ) once in a while to smoke a cigarette.请帮我理解为什么用stopping,

He was busy writing a story,only ____...He was busy writing a story,only ____ once in a while to smoke a cigarette.A、to stop B、stopping C、to have stopped D、having stopped he was busy的复数 -He is supposed _____ writing the report.-But he was really busy.A.finishingB.to finishC.to have finishedD.having finished he is busy writing something on a pice of paper. He was writing a letter at that He was busy writing a story,only ( stopping ) once in a while to smoke a cigarette.请帮我理解为什么用stopping, 19.He was busy writing a story,only _______ once in a while to smoke a cigarette.（08辽宁27） A. he was busy的复数形式(速度) He was busy yesterday一般疑问句 He was busy yesterday.改为一般疑问句 He was busy writing a story,only ____...He was busy writing a story,only ____ once in a while to smoke a cigarette.A、to stop B、stopping C、to have stopped D、having stopped 为什么不选A 为什么是伴随状语？ He was busy working throughout the night.He was busy working __________ ________ _________. father is busy writing postcards this morning and /has written /ten so far.a :was writing b:has written; 为什么? He started his own ____when he was only eighteen.(busy) he was so busy that he forgot washing his chothes Father is busy writing postcards this morning and______ten so far.A.wrote B.was writing C.has written D.has been writing为什么选D?D是什么时态? 用英语解释he is busy writing a job application改为同义句 He is busy writing an ______ for the magazine these days.