题目

以洋葱为实验材料，可以完成的实验是（） A . 鳞片叶表皮细胞呈紫色，可用于光合色素的提取和分离实验 B . 根尖细胞分裂旺盛，前期细胞可观察到四分体 C . 内表皮颜色浅，可用于检测是否有还原性糖的材料 D . 根毛区细胞具有大液泡，可用于观察水分子进出细胞的方式 答案：C8．听第9段材料，回答第13至16题．13．What are the man and the woman talking about？A．Eating in a restaurant．B．Go to a Chinese opera．C．Go to school．14．How many McDonald's were there in the world by 1982？A.7063．B.7603．C.1283．15．Why would workers buy lunches in McDonald's？A．The employees there are helpful and polite．B．The tables and floors are clean．C．The food tastes better than their lunches from home．16．Who first owned McDonald's？A．Richard McDonald．B．Two brothers．C．Ray Kroc．