417. Proper measures must be taken to limit the number of foreign tourists and great efforts should be made to protect local environment and history from the harmful effects of international tourism.
應該采取適當的措施限制外國旅游者的數量，努力保護當地的環境和歷史不受外國游客的負面影響。

六級詞匯講解:
本句是被動語態使用的典型范例，兩個并列句由and連接，不僅避免了人稱做主語，還保持了句子前后的一致性。take measures to do sth.意為“采取措施做某事”；make efforts to do sth.意為“努力做某事”；protect sth. from sth.意思是“保護某事物不受另一事物的影響”。

句型拓展:
The property taxes on the residents in the community will be raised.
社區居民的房產稅將會提高。
Initially, housing and farmland were created and established, and industry eventually followed.
一開始，人們修建房屋，開墾農田，后來又發展工業。
Parents should be encouraged to send their children to nursery schools, which will bring about profound impacts on children and families, and even the society as a whole.
應該鼓勵父母將他們的孩子送到幼兒園，這對孩子、家庭，甚至整個社會都將產生深遠的影響。