某花圃用花盆培育某种花苗，经过试验发现每盆的盈利与每盆的株数构成一定的关系，每盆植入3株时，平均单株盈利3元，以同样的栽培条件，若每盆增加2株，平均单株盈利就减少0.5元，则每盆植____ 株时能使单盆取得最大盈利；若需要单盆盈利不低于13元，则每盆需要植 ____ 株．

学者金庸说:“我们民族由于有了严密的继承制度，从而避免了内部的争斗和战争。一些游牧民族本来很强盛，但往往在关键的时候闹分裂。父亲死后，他的两个儿子或者三个儿子抢父亲位子，罗马也有这种情况。一抢位子，就要打架，就要内乱。”金庸的观点是（    ）

   Short and shy, Ben Saunders was the last kid in his class picked for any sports team. "Football, tennis Cricket — anything with a round ball, I was useless." he says now with a laugh. But back then he was the object of jokes in school gym classes in England’s rural Devonshire.
It was a mountain bike he received for his 15^th birthday that changed him. At first the teen went biking alone in a nearby forest. Then he began to cycle along with a runner friend. Gradually, Saunders set his mind building up his body, increasing his speed, strength and endurance. At age 18, he ran his first marathon.
   The following year, he met John Ridgway, who became famous in the 1960s for rowing an open boat across the Atlantic Ocean. Saunders was hired as an instructor at Ridgway’s school of Adventure in Scotland, where he learned about the older man’s cold-water exploits (成就). Intrigued, Saunders read all he could about Arctic explorers and North Pole expeditions, then decided that this would be his future. Journeys to the Pole aren’t the usual holidays for British country boys, and many people dismissed his dream as fantasy. "John Ridgway was one of the few who didn’t say, ’You are completely crazy,’" Saunders says.
   In 2001, after becoming a skilled skier, Saunders started his first long-distance expedition toward the North Pole. He suffered frostbite, had a closer encounter (遭遇) with a polar bear and pushed his body to the limit.
   Saunders has since become the youngest person to ski alone to the North Pole, and he’s skied more of the Arctic by himself than any other Briton. His old playmates would not believe the transformation.
   This October, Saunders, 27, heads south to explore from the coast of Antarctica to the South Pole and back, an 1800-mile journey that has never been completed on skis.