Concerns about public health led to the construction between 1876 and 1904 of three separate sewer systems to serve metropolitan Boston. - Concerns about public health led to the construction between 1876 and 1904 of three separate sewer systems to serve
- Concerns about public health have led to the construction of three separate sewer systems between 1876 and 1904 to serve
- Concerns about public health have led between 1876 and 1904 to the construction of three separate sewer systems for serving
- There were concerns about public health leading to the construction between 1876 and 1904 of three separate sewer systems serving
- There were concerns leading between 1876 and 1904 to the construction of three separate sewer systems for serving
答案:A 而我选的D, to serve表目的?我怎么觉得用ing表功能更能说得通呢? |