What is a reference parameter? give an example header.

and what are guidelines for when an argument should be passed by reference, and when by value?

For question 1, i'm a bit stuck between serif fonts or large enough type to read. serif fonts are good fonts to use because their easy to read. but you also need your type be large enough to read. if i had to say what you need to consider most important, i would say d is the answer.  for question 3, i believe the answer is d. it seems most appropriate to do that. on every page or every other page would be too much, and only on the contact page just seems inappropriate.  for question 4, it's probably a. by "color scheme" it doesn't mean just one color, but a set of colors. colors that are complimentary to each other. having too many is too distracting so it's best to limit it as much as possible, but not to the point where your website looks dull.hope this !

Metaprogramming  is a programming technique in which computer programs have the ability to treat programs as their data. it means that a program can be designed to read, generate, analyse or transform other programs, and even modify itself while running. ps: you don't have any options there.

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