At Christmas Eve, Jim went with his father to choose a Christmas tree. They
On（在圣诞之夜用介词on）
choose a big one. It was almost as taller as the room! They put them in the corner
chose (本文是过去时) tall（as…as之间用原级） it （指代前面的圣诞树）
of the sitting room. Kate was covered it with a lot of Christmas light . The sitting
（这里用主动语态） lights（这里是复数形式）
room looked really beautifully at the moment. There was a fire burn in the fire
beautiful（look后面接形容词作表语） burning（fire与burn构成主动关系）
place, and the Christmas tree lights were shinning brightly. Jim or his parents
and（这里表示并列关系）
∕﹨singing and dancing happily.
Were(这里使用过去进行时)
如上