Yes Zebra class s2 and s 1 are two independent courses with different difficulties. S2 is a little more difficult than s 1. After experiencing s2, you can experience s 1 to consolidate your knowledge and ability, aiming at children aged 4-6. Zebra classroom is an intelligent education platform that provides multi-disciplinary online learning for children aged 2-8. Produced by online education of ape tutor and invested by Tencent.