Before human’s history, in the middle of an ocean, miles from the nearest island, an undersea volcano broke out. The hot liquid rock piled higher and higher and spread wider and wider. In this way, an island rose up in the sea. As time went on, hot sun and cool rains made the rock split and break into pieces. Sea waves dashed against the rock. In this way, soil and sand came into being. 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 at 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 wove 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. The underlined part “in vain” can be replaced by ________. A. tirelessly    B. uselessly    C. fearlessly    D. effortlessly According to the passage, ________ made the island rise up in the sea. A. rock from the nearest island     B. sand brought by the wind C. hot liquid rock from the volcano      D. sea waves dashing against the rock What is the correct order of things appearing on the island? A. Spiders, birds and plants.  B. Soil, plants and animals C. Soil, hot liquid rock and animals.    D. Hot liquid rock, animals and plants. The passage is mainly about ________. A. how an island formed       B. how a volcano broke out C. how plants were brought to the island      D. how plants and animals began to live on the island