阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

Venice of Italy is one of the world's top tourist 【小题1】 (destination). Before the COVID-19, around 20 million visitors visited the city a year, which caused many problems such as pollution from ships and being overcrowded.【小题2】 (deal) with these problems, city officials are planning to charge tourists for visiting the city's historical centre and its beautiful canals (运河). According to Italian La Stampa newspaper, visitors may spend between 3 euros and 10 euros 【小题3】 (enter) into Venice. This probably starts from 【小题4】 summer of 2022. There are also plans to set a limit on the number of visitors 【小题5】 can enter the centre each day. 【小题6】 may be necessary for tourists to book their visit to Venice ahead of time.

Venice officials 【小题7】 (talk) for many years about the number of visitors crowding to the city. Environmentalists are 【小题8】 (extreme) worried about the damage the ships do to undersea species in the Venice Lagoon. Venice's famous squares and architecture are also ad-vised to put under the 【小题9】 (protect). Italian Culture Minister says that Venice should 【小题10】 (add) to the list of Danger Sites of United Nations' culture agency. However, a hotel worker says Venice needs tourists because they spend big.