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.
多年前,一名研究人员在山林考察时偶然看到一株开红花的木继木,而一般木继木都是开白花的。
神经系统结构和功能的基本单位是( )