保持卫生干净的英语句子可以有多种表达方式，以下是一些例子：
1. Keep the environment clean and hygienic.
2. We must keep the environment clean.
3. Please keep the bus clean.
4. Please keep the MRT clean.
5. Please keep the park clean.
6. Please keep the beach clean.
7. Please keep the mountain clean.
8. Keep clean and wash your hands.
9. Tomaintainsanitation； Keep hygienic； keepsanitary.
10. Our school keeps clean.
这些句子强调了保持不同场所的清洁和卫生的重要性，适用于个人、社区以及公共场所。