题目内容：
Questions 9—14· Read this text taken from an article about the concept of strategy of competitions.
· Choose the best sentence to fill each of the gaps.
· For each gap 9—14, mark one letter (A—H) on your Answer Sheet.
· Do not use any letter more than once.
· There is an example at the beginning, (0).
ARandom chance determined the mutations and variations that survived and succeeded to compound their numbers.
BIn the absence of some counterbalancing force that maintained a stable equilibrium between two competitors by giving each an advantage in his own territory, only one survived.
CTrue strategy was probably first practiced by one tribe attempting to take over thehunting grounds of another tribe.
DThe richer the environment, the more severe the competition and greater the number of competitors.
EPhysical and structural characteristics adapted, but behavior adapted also and became embedded in instinctual reactions.
FEach has a unique advantage in competition for its required resources with its particular niche of the environment.
GDarwin emphasized repeatedly the overriding importance of competitive： It is awesome in its potential for evolution.
HIf there had been no limitation on required resources, exponential growth would lead to infinite numbers.
根据以上资料请回答第9题：_________
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