剑桥雅思阅读长难句分析111

　　● 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。