Did you see the UFO?When it ____(landed,was landing),I was i

Did you see the UFO?When it ____(landed,was landing),I was i When the UFO(landed/was landing),the dog (slept/was sleeping I was taking a walk when the UFO landed.改成同义I ——when the UFO I was taking a shower in the bathroom when the UFO landed 的意 I was walking down the street when a UFO landed down. I was walking down the street when a UFO landed right in fro did you see anybody ____ into my room when i was away?填comin 初二英语完形填空 It was my first time to see the UFO when I was abou I( )TV when the UFO landed 翻译：I was watching TV when the alien landed . I was sleeping when the UFO arrived “I was walking down center street ,when a UFO landed .”怎么翻译