My bother came back while I_____homework.A.am doing B.was doing C.do .D,did(选什么并给予详细回答）

My bother came back while I_____homework.A.am doing B.was doing C.do .D,did(选什么并给予详细回答） He waited until my brother came back .He----- -----until my brother came back. Mum came back home when i ___(do) my homework. My father came back yesterday变一般疑问句 We didn’t have supper until my mother came back i ---(watch)TV when my parents came back I_____(finish) cleaning the house before my mother came back We didn't say anything until my father came back.We (有三空) until my father came back. I didn't have supper until my father came back.助动词之后还能用 came 为什么 When my parents ____ back home,I ____ my homework B.came,was doing D.came,did 选哪个为什么 I _______ ( finished / didn’t / finishes ) my homework until my father came back. ___ my mother ___ ___ ,my father came back (用while写) My brother was watching TV when my mother came back（用while改写） My father came back the day before yesterday.My father has ______ ______ for two days. Yesterday my father came back home as late as my mother 改为同义句 My mother was cooking when my father came back 用While改写 yesterday my farther came back home as late as my mother(同义句） I_________(feed)my pet dog when my mother came back yesterday afternoon.写出理由,