The obligation is to pay patent application fee every year.

义务就是每年都要缴纳专利申请费。

youdao

Todd: Now, each time that you applied, did you have to pay an application fee?

托德：那每次申请都要交申请费吗？

youdao

Todd: Now, each time that you applied, did you have to pay an application fee?

托德：那每次申请都要交申请费吗？

youdao