请说明为什么...While he was playing with his cat along the river ,

While he was taking a p__ with his camera, the cat went up t He got his leg ( ) while he was playing football with a grou He saw his cat was playing with a dag?是过去进行时吗? He is fishing by the river,with his son playing beside him. While Tom was playing with the balloon,he saw a plane ___ (f 4.Along with the letter was his promise ____ he would visit Along with the letter was his promise that he would visit me ( )18.Along with the letter was his promise _____ he would v WHILE I WAS DRIVING ALONG THE RIVER,I FOUND SOMETHING STRANG With his attention -------on the shops along the roadside,he He likes playing ( )the river.But there ( )a river near his Tom was ____(hurt) while he was playing soccer.And now his c