Classify the input text into either disfluent questions or proper questions. A disfluent question is a question that has some interruptions in it while framing. A proper question is the correct form of the question without any disfluency.

[EX Q]: What has the U of C maintained since 1938?
[EX A]: proper

[EX Q]: When was the Ming dynasty in power?
[EX A]: proper

[EX Q]: When are Killer T cells deactivated?
[EX A]:
proper