Directions: There are four passages in this part. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice and mark the corresponding letter on the Answer Sheet with a single line through the center. Passage 1 Questions I to 5 are based on the following passage: Thousands of years ago, in the middle of an ocean, miles from the nearest island, an undersea volcano broke out. The hot liquid piled higher and higher and spread wider and wider. In this way, an island rose up in the sea. As time went on, hot san and cool rains made the rock split and break to pieces, Sea waves dashed against the rock. In this way, soil and sand came into being.to grow taller. Nothing lived on the naked soil. And then the wind and birds brought plant seeds, spiders and other little creatures there. Only plants could grow first. Only they, in sunlight, could produce food from the minerals of the soil, water and air. While many animals landed on the island, they could find no food. A spider spun its web in vain, because there were no insects for its web to catch. Insects couldn't stay until there were plants for them to eat. So plants had to be the pioneer life on this new island. 1. The passage centers on _______. A how an undersea volcano broke out