中纬度与低纬度，中纬度与高纬度的分界线是（ ）
A：0°和30°纬线
B：30°和60° 纬线
C：0°和60° 纬线
D：60° 和30° 纬线
① The book is mine. ____ A. It's Mike's book.
② The book is Amy's. ____ B. The book is theirs.
③ It's their book. ____ C. Its' Amy's book.
④ The book is Mike's. ____ D. It's my book.
康有为、梁启超倡导变法的首要目的是（ ）
春秋争霸中谁成为中原第一个霸主（ ）
