色多多在线观看播放-色多多在线观看高清免费-色多多在线观看视频-色多多在线看-欧美aaaaa性bbbbb小妇-欧美aaaav免费大片

"The key to successful verification is to start with a clear and precise specification of what the system is supposed to do."

好的機制設計能將個人激勵與社會目標對齊。