题目

Winston Churchill is probably the most popular British prime minister ever. Having served as a soldier and politician, he is often considered among the greatest of Britons. While his heroic stand against the Nazis is well known, there are still a few facts about the popular politician that might surprise you.     His Cigars          The classic image of Winston Churchill includes a giant cigar stuck between his lips. Churchill developed his love of cigars as a young man, when he traveled to Cuba. For the rest of his life, he smoked eight or nine cigars every day. However, h生态系统的自我调节能力取决于 A．生产者和消费者的数量         B．生态系统营养结构的复杂程度 C．非生物的物质和能量水平       D．生产者和分解者的数量及种类