2016届高考英语二轮复习专项训练：选择题专练卷（4）_高考复习指南

2016届高考英语二轮复习专项训练：选择题专练卷（4）

　　NASA is aiming for a human mission to Mars by the 2030s, but experts are still not sure if humans can withstand the radiation that the journey would involve.

　　It could take eight months to reach the Red Planet, not to mention time spent on it with a thin atmosphere and no known food source, followed by an attempt at returning to Earth.

　　One recent study found that with the current limits of technology, adventurers to Mars would start dying in 68 days. Another study this week said the risk of radiationinduced cancer would limit any trip to one year.

　　NASA considers it just as important to study whether people’s mental states could hold up under the pressure of a Mars journey, said principal investigator Kim Binsted.

　　Both crew psychology and radiation are considered “red risks” for Mars, “which means essentially, until we solve these problems, we are not going，” Binsted told AFP. Binsted is coordinating the experiment from the outside the dome. Those inside are healthy, educated people in their 20s and 30s, each with a keen interest in science and space. “It is kind of the opposite of a reality show. We select against drama.” explained Binsted. “We try to pick a crew that will get along with each other. We pick generally levelheaded and easygoing people.”

　　They include Allen Mirkadyrov, an aerospace engineer for and Neil Scheibelhut, a microbiologist and former soldier in Iraq. Sophie Milam is an expert in robotics who is pursuing a master’s degree in engineering, and Zak Wilson is a mechanical engineer. The commander is Canadianborn Martha Lenio, who earned a doctor degree in engineering and has worked in the sustainable building industry, according to her biography.