Before revision:  To address this, lexically constrained NMT explores various methods to ensure pre-specified words and phrases to appear in the translations. In many cases, however, those methods are evaluated on general domain corpora, where the terms are mostly uni- and bi-grams (>98\%).
After revision:  To address this, lexically constrained NMT explores various methods to ensure pre-specified words and phrases to appear in the translation output. However, in many cases, however, those methods are evaluated on general domain corpora, where the terms are mostly uni- and bi-grams (>98\%).