Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks.
Ha Long Bay is a UNESCO World Heritage Site and popular travel (23)_______ in Quang Ninh Province, Vietnam. The bay features of thousands of limestone karsts and isles in various shapes and sizes. Ha Long Bay is a center of a larger zone which (24)______ Bai Tu long Bay to the northeast, and Cat Ba island to the southwest.
Ha Long Bay has an area of around 1,553km2 , including 1,9600 – 2,000 islets, most of (25)______ are limestone. The core of the bay has an area of 334km2 with a high density of 775 islets. The limestone in the bay has gone through 500 million years of formation in different conditions and environments. The evolution of the karst in this bay has taken 29 million years (26)_______ the impact of the tropical wet climate. The geo-diversity of the environment in the area has created (27)________ , including a tropical evergreen biosystem, ocenic and sea shore biosystem. Ha Long Bay is home to 14 endemic floral species and 60 endemic faunal species.
(23).....................
