我有两篇论文要写，然后还有我的科学项目要完成。

I've got two essays to write and ___then my science project to finish.

这是标准型号，然后还有豪华版本，价格更高。

This is the standard model, ___then there's the luxury version which costs more.

她全职工作，然后周末还做志愿者。

She works full-time, and ___then she also volunteers on weekends.