英语翻译古城墙有极高的历史价值,是城市文明象征之一.文化遗产有利于我国与世界各国的文化交流

Ancient city wall has high historical value, and it is one of the urban civilization symbol.
Cultural heritage is advantageous to the cultural exchange between our country and the whole world.

原句1：古城墙有极高的历史价值，是城市文明象征之一。
Ancient city wall has high historical
value, is one of the symbols of urban civilization.
原句2：文化遗产有利于我国与世界各国的文化交流。
Cultural heritage in favour of cultural
exchanges between China and countries around the world.
求赞！~

修建公路是社会发展的需要.

Highway/Road paving(铺设,修建) is the requirement of social development.

Road-building(筑路,单一词) is the need for development of society.

修建,偏于“建”,建筑、筑路、铺路

文化遗产在必要时应给社会发展让路.

Cultural heritages shall give way to social development when necessary.

Culture heritage should make way for social development when in necessity.

在必要时,做状语,修饰全句

when necessary=when it is necessary；when in necessity同理

古城墙有极高的历史价值,是城市文明象征之一.

Ancient city wall is of high historical value, and thus is one of the symbols for urban civilization.

be of value,固定搭配,有价值

symbols for urban civilization=urban civilization symbols 

文化遗产有利于我国与世界各国的文化交流

Cultural heritages are in favor of cultural exchange between China and other nations.

Culture heritages is beneficial to cultural communication between our country and nations around the world.

有利于,in favor of、make for、avail、to the benefit of

供参

The development of society is in need of roads building.
Cultural heritage should make way for the social development when it is necessarily to do so.
Ancient city wall has high historical value, and it is one of the urban civilization symbol.
Cultural heritage is advantageous to the cultural exchange between our country and the whole world.

满意的话记得采纳啊