晚上太阳下山时，小明面对太阳，请问小明的身后是____。
夏天更容易闻到各种气味，说明分子运动的快慢与____ 有关．冬天烤火取暖是通过____ 的方式增加人体内能的．
Life was very different in China many years ago.
One day Eddie and Hobo looked at the ____. Eddie thought he saw a____but Hobo thought it was a ____. Because Hobo saw one ____. Eddie thought there were many bright ____and it was too____, so it couldn't be a plane.
