Final answer:
To order the topics by scope, we start with the 'historic infrastructure projects of the 20th century' as the broadest, followed by 'infrastructure projects by the Public Works Administration', then 'historic projects of Roosevelt's New Deal', and finally the narrowest, 'bridge-building projects by the Public Works Administration'.
Step-by-step explanation:
To order the topics from broadest to narrowest, one would look at the scope of each topic and how many areas or aspects it includes. The broadest topic would encompass the greatest amount of information, while the narrowest would be highly specific. Below is the list ordered based on their scope:
- Historic infrastructure projects of the 20th century
- Infrastructure projects conducted by the Public Works Administration
- Historic infrastructure projects of President Roosevelt's New Deal
- Bridge-building projects conducted by the Public Works Administration
The historic infrastructure projects of the 20th century is the broadest category as it would not only include those done under the Public Works Administration but all others during that time period globally. The infrastructure projects conducted by the Public Works Administration is narrower because it focuses only on the projects undertaken by that specific agency. The historic infrastructure projects of President Roosevelt's New Deal narrows this focus further to those that were carried out during his tenure. Lastly, the bridge-building projects conducted by the Public Works Administration is the narrowest topic as it is confined to only bridge-building efforts by the PWA.