请问我们的成绩到底是算哪个SYSTEM??

我给阿姆斯特丹大学发的邮件问它硕士录取要求,结果它回我的关于成绩的东东:
* Grade average
If you wish to apply for the research master's programme in Psychology you are
expected to have an overall grade point average (GPA) of at least an
A/ 4.0 (American system)
2.1 HONS (an upper second class honours degree in the British system)
B (ECTS stystem), or
7.5 (Dutch system)

不知道我们中国的成绩到底怎么算,算哪个呀???换成平均分或者基点应该是多少啊?

自己来挺一下先,请各位前辈帮忙指教啊~~~