2017雅思阅读长难句例句分析（3）

　　题目：

　　Therefore, like the timber barriers, the Fanwall barrier can be built without expensive concrete footings or piles, speeding the construction time up and reducing costs.

　　分析：

　　can be built是被动语态，like the timber barriers是介词短语做状语，speeding the construction time up and reducing costs是分词短语做状语。