Strategies emerge one after another, used to defend themselves and fight back, and those who attack can not use but must learn Strategies emerge one after another, used to defend themselves and fight back, and those who attack can not use but must learn Strategies emerge one after another, used to defend themselves and fight back, and those who attack can not use but must learn Strategies emerge one after another, used to defend themselves and fight back, and those who attack can not use but must learn Strategies emerge one after another, used to defend themselves and fight back, and those who attack can not use but must learn Strategies emerge one after another, used to defend themselves and fight back, and those who attack can not use but must learn