city cluster的用法和样例：
例句
- Howerver the current development of the PRD city clusters is far from being a strategic platform for the national wealth accumulation.
但目前珠三角城市群的发展远未形成国家财富积聚的战略平台。 - The functions of the industry clusters in thedevelopment of city groups include the drive mecha-nism and restriction mechanism.
产业集群在城市群发展中的作用机制有驱动机制和约束机制。
