单词竞猜：根据中文或首字母提示，结合句意写出空白处各单词的正确形式。
1. Scientific study of the origin, history, and structure of the earth. g___________
2. Large area of flat land higher than the land around it p___________.
3. Tom has left the army and is now an ordinary____________. c___________
4.The artist______（雕刻）a statue of the president out of wood. ___________
