Proper- ties的用法和样例：
例句
- No default is provided, but it is essential to use proper settings here to get the best server performance.
没有缺省值，但在这里使用适当的设置以获取最佳服务器性能是必须的。 - Engine parts, particularly the piston, must be kept free of varnish to ensure performance and proper cooling.
发动机零件尤其是活塞，必须保持光泽以确保性能和正确的冷却。
