单选题
Read the following passage and decide which answer best fits each space. For questions 26~45, mark one letter A, B, C or D on the Answer Sheet. Both【C1】______and zoology are parts of a more general field of science, biology. The two are studies of【C2】______things, which share certain characteristics,【C3】______they are plants or animals. Botany deals with plants, whose organisms that can【C4】______their own food by the use of sunlight. Zoology on【C5】______hand, deals with animals, those organisms that cannot manufacture their own food and are thus dependent【C6】______plants for their food. 【C7】______plants and animals share many abilities, the extent【C8】______which plants can exercise some of those abilities is【C9】______. For example, both plants and animals need food, water, and warmth for growth,【C10】______plants can move to【C11】______those needs only by the slow extraction of their leaves and roots, while animals can move relatively【C12】______distances in relatively little time. When an animal is hurt with needle, the animal will【C13】______the part of the body【C14】______. This ability to draw back【C15】______pain or irritation, called irritability, is found only to a very limited extent in plants. If plants【C16】______the same【C17】______as animals, animals would have had a more difficult time finding food. If animals were as limited as plants, they might【C18】______a means of manufacturing their own food, as plants do now. The world would be a very different place【C19】______it is if the characteristics of plants and animals were【C20】______.