People / know / Ha Long Bay / recognise / UNESCO. People know that Ha Long Bay is recognised by UNESCO 21/38People / know / Ha Long Bay / recognise / UNESCO.People know the Ha Long Bay is recognised by UNESCOPeople know that Ha Long Bay is recognised by UNESCO People know that Ha Long Bay are recognised by UNESCO People know that Ha Long Bay is recognise by UNESCOGiải thíchĐáp án đúng là B