【原】句子分析

1.     The Hong Kong West Drainage Tunnel is the largest of four, and runs through the mountains above Tin Hau, in the eastern part of the island, past the busy financial districts of Admiralty and Central, to Cyberport on the western coast. At its widest, the tunnel is 7.25 meters in diameter.

该句用了三个介词，分别是in，past，to，来详细地解释说明The Hong Kong West Drainage Tunnel的长度和所经过的范围。运用多个介词串联句子成分，详细解释说明The Hong Kong West Drainage Tunnel这个隧道的长度。

2.     So, rural villages and towns can be protected with dykes and channels dug to redirect or temporarily store the water, while heavily built-up, urban areas require more intensive engineering work.

While的作用是引起前后两个句子的对比。写出了乡村和城镇与城市的地下排水通道建设的难度对比。

3.     These solutions, which direct rainwater away from vulnerable areas and eventually return it to the ocean, have helped to reduce the number of flooding blackspots from 126 in 1995, to just five today.

Which引导的是非限制性定语从句，解释说明了these solutions的作用；同时这个也属于插入句，真正的主语是these solutions，真正的谓语是have helped to reduce。所以这句的理解可以是：These solutions（, which direct rainwater away from vulnerable areas and eventually return it to the ocean, ）have helped to reduce the number of flooding blackspots from 126 in 1995, to just five today.从而可以更好的理解句子意思，分清主语谓语。

4.     Combined with the city's typhoon warning and protection systems -- such as storm surge barriers -- it has made weather that is disastrous in many other parts of southeast Asia a mere annoyance for most Hong Kongers.

combined with 是非谓语动词，主语是it，谓语是has made。Weather后跟了that从句，解释了这个weather对许多香港人造成的困扰。For是介词状语，表明对象，是most Hong Kongers。

5.     Some of the water that falls on the racecourse is collected and reused, for irrigation and to flush toilets in nearby housing estates.

因为water是不可数名词，所以用some of来修饰。That从句，跟在了water后面，是定语从句，说明了water的具体意思，即说明了water是落在赛马场上的。

在Some of the water that falls on the racecourse is collected and reused中，Some of the water that falls on the racecourse作为整句的主语，谓语是is collected and reused。For和to是介词，表目的；

6.     It protects some of the most expensive real estate in the city from flooding, not least the racecourse itself, which prior to the tank's creation in 2012 was regularly inundated with rain, destroying the turf and requiring expensive repairs.

该句主语是It,谓语是protects。Which引导非限制定语从句。解释说明It protects some of the most expensive real estate in the city from flooding, not least the racecourse itself这种情况发生的原因。