TASK DEFINITION: Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
PROBLEM: Possible Duplicate: 'If I was' or 'If I were'. Which is more common, and which is correct? Is this correct grammar? What if there was a Stack Overflow on Shouldn't it be 'what if there were a Stack Overflow on'?.

SOLUTION: Prescriptively, you're correct, this should be were since this is being expressed with the subjunctive mood. Descriptively, I think you'll find both in the wild. In informal speech, most people I know would prefer was in this case (and those that don't are sticklers for the subjunctive). I do think that you are much more likely to see were written though, especially in formal writing. Either form is correct, and the subjunctive forms are far from dead. A more interesting question, I think, is whether or not the subjunctive mood is still being used and if the two forms have simply collapsed together. Is this a meaningful distinction? How could this be tested?

PROBLEM: Please tell the single word for 'to completely root out a disease'.

SOLUTION: Eradicate. Etymology is from Eradicare. Eradicare, in turn, can be traced back to the Latin word radix, meaning 'root' or 'radish.' Although eradicate began life as a word for literal uprooting, by the mid-17th century it had developed a metaphorical application to removing things. Eradication is the reduction of an infectious disease's prevalence in the global host population to zero.

PROBLEM: This came up recently on programmers.SE, when someone (a Russian, presumably non-native English speaker) asked why we used the term 'sister sites', instead of 'brother sites'. Of course, I'm a native English speaker, and I have no idea either, hence this question. The full question, for context, was 'Several of our sister sites have taken to featuring Questions [...]'. It does seem odd, considering that English (usually) uses masculine terms as the default.

SOLUTION:
I suspect the terminology sister sites is derived from sister cities. Traditionally, cities, countries, and ships have been personified as feminine in English, although this is growing less common due to the influence of women's rights.