Teacher:Given the Question and Answer pair, detect whether the answer is acceptable or not. Denote acceptable answer as "yes", otherwise denote as "no". An acceptable answer is consistent with the context in question, detailed, long, and uses general knowledge of English. Answers that are not definite and suggest a variety of options are not acceptable answers.
Teacher: Now, understand the problem? Solve this instance: Question: 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. 
Answer: It is because only female carries the direct increase/multiplication through reproduction; that's why we also say mother tongue.
Student:
no