第9题: [单项选择]胰岛A细胞分泌______ A. 胰多肽 B. 胰高血糖素 C. 生长激素抑制激素 D. 胰岛素 E. 降钙素 参考答案:B 答案解析:[解析] 胰岛主要分为A细胞、B细胞、D细胞及PP细胞。A细胞约占胰岛细胞的20%,分泌胰高血糖素;B细胞占胰岛细胞的60%~70%,分泌胰岛素;D细胞占胰岛细胞的10%,分泌生长抑素;PP细胞数量很少,分泌胰多肽。
第10题: [单项选择]Few people realize ______. A. how quickly many species of cacti are becoming extinct B. how quickly much species of cacti is becoming extinct C. how quickly are many species of cacti becoming extinct D. how quickly is much species of cacti becoming extinct 参考答案:A 答案解析:句意:几乎没人意识到仙人掌物种的消失速度之快。species是可数名词,故排除B项和D项;根据感叹句的句型排除C项。