Question: Additionally, there are issues of connections between different electrical services, particularly connecting intercity lines with sections electrified for commuter traffic, but also between commuter lines built to different standards. This can cause electrification of certain connections to be very expensive simply because of the implications on the sections it is connecting. Many lines have come to be overlaid with multiple electrification standards for different trains to avoid having to replace the existing rolling stock on those lines. Obviously, this requires that the economics of a particular connection must be more compelling and this has prevented complete electrification of many lines. In a few cases, there are diesel trains running along completely electrified routes and this can be due to incompatibility of electrification standards along the route.
Is there an answer to this question: Why the commuter lines built to different standards can cause be complicated?

Answer: the implications on the sections it is connecting

Question: Northwestern is a large, residential research university. Accredited by the North Central Association of Colleges and Schools and the respective national professional organizations for chemistry, psychology, business, education, journalism, music, engineering, law, and medicine, the university offers 124 undergraduate programs and 145 graduate and professional programs. Northwestern conferred 2,190 bachelor's degrees, 3,272 master's degrees, 565 doctoral degrees, and 444 professional degrees in 20122013.
Is there an answer to this question: How many graduate and professional programs are offered by Northwestern?

Answer: 145

Question: Industries slowly brought the city and its inhabitants back to a renewed vitality and jobs attracted new residents. As the city's commerce improved, residents worked to restore or create community institutions. In 1865, the Avery Normal Institute was established by the American Missionary Association as the first free secondary school for Charleston's African American population. General William T. Sherman lent his support to the conversion of the United States Arsenal into the Porter Military Academy, an educational facility for former soldiers and boys left orphaned or destitute by the war. Porter Military Academy later joined with Gaud School and is now a university-preparatory school, Porter-Gaud School.
Is there an answer to this question: What type of school was the Avery Normal Institute?

Answer: free secondary school

Question: Most copper is mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits that contain 0.4 to 1.0% copper. Examples include Chuquicamata in Chile, Bingham Canyon Mine in Utah, United States and El Chino Mine in New Mexico, United States. According to the British Geological Survey, in 2005, Chile was the top mine producer of copper with at least one-third world share followed by the United States, Indonesia and Peru. Copper can also be recovered through the in-situ leach process. Several sites in the state of Arizona are considered prime candidates for this method. The amount of copper in use is increasing and the quantity available is barely sufficient to allow all countries to reach developed world levels of usage.
Is there an answer to this question: From what types of mines is copper extracted?

Answer:
open pit mines