四川省眉山市2014
高考英语阅读理解、完形填空专题训练（12）附答案 .阅读理解 words：408 难度系数：★★★ 建议用时：9分钟 as bananas ripen，the green skin turns yellow gradually.chemical changes occur in the flesh of the fruit as well：starch(淀粉) changes to sugar；pectin(果胶) breaks down，losing its stiffness；and the flesh softens. is ripening fruit a selfcontained system，or is the rate of these changes affected by the environment?
