C 'Reduce, reuse and recycle, this familiar environmentalist slogan tells us how to reduce the amount of rubbish that ends up in landfills and waterways. The concept is being used to deal with one possibly dangerous form of waste –--- electronic junk (电子垃圾), such as old computers, cell-phones, and televisions. But this process for managing e-waste may be used in an unscrupulous（不择手段的） way more often than not used, a recent report suggests. “A lot of these materials are being sent to developing nations under the excuse of reuse –--- to bridge the digital divide,” said Richard Gutierrez, a policy researcher. One of the problems is that no one proves whether these old machines work before they hit the seaways. Because of this, the report says, e-waste is a growing problem in Lagos, Nigeria, and elsewhere in the developing world. Much of the waste ends up being thrown away along rivers and roads. Often it’s picked apart by poor people, who may face dangerous exposure to poisonous chemicals in the equipment. Businessmen also pay workers a little money to get back materials such as gold and copper. This low-tech recovery process could expose workers and the local environment to many dangerous materials used to build electronics. According to Gutierrez, this shadow economy exists because the excuse of recycling and reusing electronics gives businessmen “a green passport” to ship waste around the globe. “Developing nations must take upon some of the responsibility themselves,” Gutierrez said. But, he added, “A g reater portion of this responsibility should fall on the exporting state.” China, for example, has become a dumping（倾倒，堆放） place for large amounts of e-waste. The nation is beginning to take action to stop the flow of dangerous materials across its borders. The Chinese government, after many years of denial（否认）, is finally beginning to take the lead. 70．What does the fourth paragraph mainly discuss? A. Old computers and TVs still work before they are sent abroad. B. Poor people break up e-waste to collect some valuable materials. C. A lot of e-waste is dumped in developing countries. D. The problem of e-waste is growing in developing countries. 71．From what Gutierrez said we can learn that ________. A. exporting countries should mainly be responsible for this problem. B. neither rich nor poor countries should be blamed for this problem C. developing countries should be responsible for this problem D. poor countries should be blamed for this problem 72．It can be inferred from the last paragraph that _______. A. China has hidden a large amount of e-waste in many secret places B. China has greatly changed the idea about the problem of e-waste C. China has prevented poisonous materials from entering China for a long time D. China is falling behind other countries in dealing with e-waste 73．The passage mainly tells us that _______. A. developing countries are facing serious environmental problems B. e-waste is a growing problem in developed countries C. e-waste is sent to developing countries under the excuse of reuse D. developing countries are making full use of e-waste