单项选择题 雅可比矩阵是不对称矩阵，但定雅可比矩阵是对称矩阵。 A、正确 B、错误

多项选择题 The general rules for disease occurrence and development include A、Disruption of homeostasis. B、Process of damage and anti-damage. C、Reversal role of cause and result. D、Correlation between systemic and local regulation.

不定项选择 我国服务贸易起步于20世纪80年代，虽然起步较晚但发展速度较快。（    ）