A:采猎文明时期,人受地的制约比较小
B:农业文明时期,人地关系得到和谐发展
C:产业革命之后,人地关系开始出现矛盾,局部地区产生环境问题
D:到了近代,人们对人地关系的认识逐渐走向系统化和科学化
—No wonder the emperors all wear clothes with dragons.
(Ⅰ)∠ECD=∠EBD;
(Ⅱ)2DB2=PD•DE.
—It is 7657457.
There __________ a big tree in front of my house . I could hear many birds sing in it .