tokens: We thank the anonymous referee for a careful reading of our manuscript and for constructive comments and suggestions, which improved the paper. HIFI has been designed and built by a consortium of institutes and university departments from across Europe, Canada, and the United States under the leadership of SRON Netherlands Institute for Space Research, Groningen, The Netherlands, and with major contributions from Germany, France, and the US. Consortium members are: Canada: CSA, U.Waterloo; France: CESR, LAB, LERMA, IRAM; Germany: KOSMA, MPIfR, MPS; Ireland: NUI Maynooth; Italy: ASI, IFSI-INAF, Osservatorio Astrofisico di ArcetriINAF; Netherlands: SRON, TUD; Poland: CAMK, CBK; Spain: Observatorio Astronmico Nacional (IGN), Centro de Astrobiologia (CSIC-INTA); Sweden: Chalmers University of Technology MC2, RSS GARD, Onsala Space Observatory, Swedish National Space Board, Stockholm University Stockholm Observatory; Switzerland: ETH Zurich, FHNW; USA: Caltech, JPL, NHSC. L.J. and Y.G. acknowledge support by NSFC grant nos. 11311130491 and 11420101002 and CAS Key Research Program of Frontier Sciences B program no. XDB09000000.
ner_tags: O O O O O O O O O O O O O O O O O O O O O O B-Instrument O O O O O O O O O O O O O O O B-Location B-Location O O B-Location I-Location O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Location I-Location I-Location O O O O O B-Location B-Location O O B-Location O O O B-Location B-Organization B-Organization B-Location B-Organization B-Organization B-Organization B-Observatory B-Location B-Organization B-Organization B-Organization B-Location B-Organization I-Organization B-Location B-Organization B-Organization B-Observatory I-Observatory I-Observatory I-Observatory B-Location B-Organization B-Organization B-Location B-Organization B-Organization B-Location B-Observatory I-Observatory I-Observatory B-Observatory B-Organization I-Organization I-Organization B-Organization B-Location B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization I-Organization B-Observatory I-Observatory I-Observatory B-Organization I-Organization I-Organization I-Organization B-Organization I-Organization B-Observatory I-Observatory B-Location B-Organization I-Organization B-Organization B-Location B-Organization B-Organization B-Organization O O O O O O O O O O O O O O O O O O O O O O O O