regarding the contributions of our paper comparing with two lines of previous work, which we make clear first

We want to express our gratitude to all the reviewers for careful reading and valuable comments. To begin with, we want to apologize for the typos and unclear writings. We will correct them in the final version, and add the broader impact section. The first line of research is the various (unbiased) propensity estimation methods in the recommendation literature. The other line of prior work is distribution-robust optimization (DRO), which is a vast domain.