Variable ratio
Among the reinforcement schedules, variable ratio is the most productive and the most resistant to extinction. Fixed interval is the least productive and the easiest to extinguish (Figure 1).
Cristiano Ronaldo dos Santos Aveiro GOIH, ComM (European Portuguese: [kɾiʃˈtjɐnu ʁoˈnaɫdu]; born 5 February 1985) is a Portuguese professional footballer who plays as a forward for Spanish club Real Madrid and the Portugal national team. Often considered the best player in the world and widely regarded as one of the greatest of all time,[note 1] Ronaldo has five Ballon d'Or awards,[note 2] the most for a European player and is tied for most all-time. He is the first player in history to win four European Golden Shoes. He has won 25 trophies in his career, including five league titles, four UEFA Champions League titles and one UEFA European Championship. A prolific goalscorer, Ronaldo holds the records for most official goals scored in the top five European leagues (391), the UEFA Champions League (117), the UEFA European Championship (29) and the FIFA Club World Cup (7), as well as most goals scored in a UEFA Champions League season (17). He has scored more than 600 senior career goals for club and country.Lionel Andrés Messi Cuccittini[note 1] (Spanish pronunciation: [ljoˈnel anˈdɾez ˈmesi] ( listen);[A] born 24 June 1987) is an Argentine professional footballer who plays as a forward for Spanish club Barcelona and the Argentina national team. Often considered the best player in the world and regarded by many as the greatest of all time, Messi has a record-tying five Ballon d'Or awards,[note 2] four of which he won consecutively, and a record-tying four European Golden Shoes.[note 3] He has spent his entire professional career with Barcelona, where he has won 30 trophies, including eight La Liga titles, four UEFA Champions League titles, and five Copas del Rey. Both a prolific goalscorer and a creative playmaker, Messi holds the records for most official goals scored in La Liga (374), a La Liga season (50), a club football season in Europe (73), a calendar year (91), El Clásico (25), as well as those for most assists made in La Liga (149) and the Copa América (11). He has scored over 600 senior career goals<span> for club and country.
</span>Zinedine Yazid Zidane <span>O.L.H., A.O.M.N.</span><span> (</span>French pronunciation: [zinedin zidan], born 23 June 1972), nicknamed "Zizou<span>", is a French retired professional </span>footballer<span> and current manager of </span>Real Madrid<span>. He played as an </span>attacking midfielder<span> for the </span>France national team<span>, </span>Cannes<span>, </span>Bordeaux<span>, </span>Juventus<span> and Real Madrid.</span>[3][4]<span> An elite </span>playmaker<span>, renowned for his elegance, vision, ball control and technique, Zidane was named the best European footballer of the past 50 years in the </span>UEFA Golden Jubilee Poll<span> in 2004.</span>[5]<span> He is widely regarded as one of the greatest players of all time.</span>[6][7]<span>[8]</span><span>
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Answer:
headache , general aches and pain ,loss of appetite, indigestion, grinding of teeth , problem sleeping
