He was busy ___ (do)his homework while I was cooking这道题为什么要用非谓语中的动名词形式doing呢?

He was busy ___ (do)his homework while I was cooking这道题为什么要用非谓语中的动名词形式doing呢? he was busy的复数 ___ he busy the day before yesterday?A、Were B、Was C、Did he was very busy yesterday ,otherwise he ___ to the meeting为什么选 would have come 请高手讲讲. My mother is ill,so I have to stay at home and___ ___ ___ ___ ___（照看）herEvery day he is___ ___（实在太）busy,because he has ___ ___（太多）work to do. He made me do that for him = I was ___ ___ ___do that for him 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 再下面句子里填上said、told,并用括号中动词的正确形式填空.What ___ he ___ that he ____(do)?When ___ you that he ___(buy) this car?Why ____ you ____ that you ____(be) busy? He was busy working throughout the night.He was busy working __________ ________ _________. when he was ___,he went down to the small river behind the factory and tries to catch it .A free B busy C ill D right 一道英语题（虚拟语气）He ____ busy yesterday,or he ___ you with your experiment.was,would have helped He did not help his mother do homework until he was 15同义句 he ___ ___ ____his mother do housework at the age of 15. He started his own ____when he was only eighteen.(busy) he was so busy that he forgot washing his chothes There was once a manager.He was busy all day.……Now here is the note：IM2B2CU Do you know what itmeans? The policeman asked him ___ when the accident happended.A what was he doing B what did he do C what he was doing D what he did