8. Proper measures must be taken to limit the number of foreign tourists and the great efforts should be made to protect local environment and history from the harmful effects of international tourism.

应该采取适当的措施限制外国旅游者的数量，努力保护当地环境和历史不受国际旅游业的不利影响。

9. An increasing number of experts believe that migrants will exert positive effects on construction of city. However, this opinion is now being questioned by more and more city residents, who complain that the migrants have brought many serious problems like crime and prostitution.

越来越多的专家相信移民对城市的建设起到积极作用。然而，越来越多的城市居民却怀疑这种说法，他们抱怨民工给城市带来了许多严重的问题，像犯罪和卖淫。