It's not high mountains and deep valleys that best serve to defend a country.
固国不以山溪之险。
《新英汉大辞典》
2
Do the public exist to serve public-sector workers with their high pay and inflated benefits, they ask, or do public-sector workers exist to serve the public?
到底应该是老百姓服务这些拿着高工资、高福利的公共部门雇员，还是应该由他们来服务老百姓？
3
First, a lack of competition within the market and the corresponding high cost of SI systems serve to restrain growth.