A:生产关系的变革
B:社会生产力的发展
C:社会制度的变革
D:人类思维和文化的发展
A: Look! What beautiful pictures of flowers they are! ____
B: No, they are not mine.
A: ____
B: They are my father's.
A: Good job! Your father is a great man.
如果y=(m+2)x+m﹣1是常值函数,那么m=____