2006年，上海水产市场发出通知，要求即日停止销售多宝鱼．经上海市药监局抽检的30件多宝鱼样品中全部检出硝基呋喃类代谢物，且最高检出值为1mg/kg左右．硝基呋喃类药物为禁用渔药，长期摄入存在致癌可能．我校生物兴趣小组想利用以下材料，设计实验探究“硝基呋喃类药物”是否可能诱导动物致癌，请你为他们完成下列实验设计和预测实验结果并分析．

（一）实验题目：探究“硝基呋喃类药物”是否可能诱导大鼠致癌．

（二）材料用具：大鼠若干只；普通饲料；三种不同剂量的硝基呋喃类药物溶液A、B、C（分别为低、中、高浓度）；纯净水等．

（三）步骤设计：（请简要写出）

第一步：选取____ 大鼠若干只；随机平均分成四组，编号甲、乙、丙、丁；

第二步：实验组____ ；

对照组____．

第三步：____ ；

第四步：两年后，检查大鼠的健康状况，统计各组大鼠癌病的发生率．

（四）实验结果预测与结论：

（1）如果____ ，说明硝基呋喃类药物不会诱导大鼠癌病的发生；

（2）如果甲组、乙组、丙组大鼠癌病的发生率相近，且高于丁组，说明____ ．

（3）如果____ ，说明硝基呋喃类药物会诱导大鼠癌病的发生，而且剂量越高，诱导大鼠癌病的发生率越高．

（五）若“硝基呋喃类药物”能诱导大鼠致癌，且与用药剂量无关．请在此基础上提出一个继续探讨的课题．____ 

阅读理解

    Singapore is building an airport where indoor trees, waterfalls and a 'rain vortex' sit alongside check-in queues, waiting rooms and baggage carousels(传送带).

    Where once sat a car park, there will soon be thousands of trees and plants across 22,000 square metres of landscaped indoor parklands. This will be joined by a 40m-high indoor waterfall, expected to be the world's tallest. These are the plans for the new 3.5 hectare 'Jewel' development at Singapore's Changi Airport, scheduled to open in 2018; a five-story, 134,000 square metre complex, mixing natural outdoor plants with modern airport facilities.

    “The aim behind the introduction of such lush(茂盛的) landscaping is purely to provide all visitors with a memorable experience, one where they are surrounded by nature and greenery,”says Philip Yim, Chief Executive Officer of Jewel Changi Airport Development.

    Promised sustainability（持续性） measures include “extensive usage of photovoltaic panels（光电板）”to produce renewable energy, as well as encouraging the use of natural lighting and a “high efficiency” air-conditioning system.

    The indoor waterfall, named the “Rain Vortex”, will make use of special lighting effects to change at night into what is promised to be a dramatic light and sound show. “The Rain Vortex is one example of how sustainable design plays an important role in the planning of the attraction,” says Yim. 'In the event of a rain storm, the power of the rain water will flow naturally through the oculus. The excess rain water collected will be used for irrigation of the landscaping at Jewel.'

    Yim quotes the popular reputation Singapore enjoys as “the garden city”, where greenery is recognised as an essential part of the urban landscape, an attractive image which clearly inspires Jewel's design.

    However, it remains to be seen whether, beyond the aesthetic (审美的) appeal, Jewel can add genuine environmental things to something as un-environmental as an international airport.