Before revision:  To mitigate large-scale annotations  , domain adaptation (DA) provides an alternate solution by learning a transferable model from another labeled source domain. Since the labeled data may be from multiple sources, multi-source domain adaptation (MDA) would be more practical to exploit the complementary information from different domains.
After revision:  To mitigate large-scale annotations , domain adaptation (DA) provides an alternate solution by learning a transferable model from other labeled source domains. Existing multi-source domain adaptation (MDA) would be more practical to exploit the complementary information from different domains.