D．The number of rhinos dropped to the lowest.

　　解析：选B　细节理解题。由第一段中的"a total of 1,004 rhinos were poached"和"It was also the most South African rhinos killed in one year"可知，2013年共有1 004头犀牛被偷猎，是南非最多犀牛被捕杀的一年。

　　2．Why do some Asians want to buy rhino horns?

　　A．To seek pleasure.

　　B．To do experiments.

　　C．For health benefits.

　　D．For personal collection.

　　解析：选C　推理判断题。由第三段中的"the horns are used as key ingredients in traditional Asian medicines"和"Some people believe taking ground­up rhino horn can help treat pain, fevers, and cancer"可知，在一些亚洲国家，人们出高价来买犀牛角，因为他们认为吃犀牛角粉有利于健康。

　　3．What is the focus of Paragraph 4?

　　A．The serious situation of rhinos.

　　B．The importance of protecting rhinos.

　　C．The measures taken to protect rhinos.

　　D．The causes of rhinos' being endangered.

　　解析：选A　段落大意题。由第四段的描述可知，本段主要讲述了目前世界上犀牛的处境堪忧。

　　4．What does Tom Milliken think of rhino poaching?

　　A．It endangers other wildlife.

　　B．It is dangerous and damaging.

　　C．It helps to develop the economy.

　　D．It has been brought under control.

　　解析：选B　推理判断题。由最后一段中的"stop this stealing of southern Africa's natural heritage"和"Rhino­horn trafficking represents a threat to the basic structure of society"可知，Tom Milliken 认为偷猎犀牛是对非洲南部自然遗产的偷窃，走私犀牛角是对社会基本结构的威胁。

　　B

　　"Once there was the Stone Age, then the Bronze Age, and now we are in the middle of the Plastic Age，" said teenager Boyan Slat. "Every year, we produce 300 million tons of plastic. Much of it reaches our oceans."

At the age of 16, Boyan Slat scuba dived off Greece in the Mediterranean Sea seeing more rubbish floating on and under the surface. He said, "At first, I thought I was swimming through strange jellyfish. Instead, I swam through more plastic bags than fish." Seeing all the ocean trash, he