1 . Directions: Complete the following passage by using the words in the box. Each word can only be used once. Note that there is one word more than you need.

A. curiosity       B. foundation       C. madness       D. means       E. multiple       F. overlooks G. overstates     H. possible          I. push             J. reduce       K. special

Restless Genes

“No other mammal (哺乳动物) moves around like we do,” says Svante Pääbo, a director of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. He uses genetics to study human origins. “There’s a kind of     1     to it. Sailing out into the ocean, you have no idea what’s on the other side. And now we go to Mars. We never stop. Why?”

If an urge to explore rises in us at birth, perhaps its     2     lies within our genome. In fact, there is a mutation (突变) that pops up frequently in such discussions: a variant of a gene called DRD4. DRD4 helps control dopamine, a chemical messenger in the brain that plays a major role in reward-motivated behavior. Researchers have repeatedly tied the variant DRD4-7R—carried by roughly 20 percent of all humans—to increased     3     and restlessness. Dozens of human studies have found that 7R makes people more likely to take risks: explore new places, ideas, foods, or relationships; and generally love movement, change, and adventure.

So is 7R the explorer’s gene or adventure gene, as some call it? Yale University evolutionary and population geneticist Kenneth Kidd thinks that this     4     its roles. Kidd speaks with     5     authority here, as he was part of the team that discovered the 7R variant 20 years ago. “You just can’t     6     something as complex as human exploration to a single gene.” It would be better, Kidd suggests, to consider how groups of genes might lay foundation for such behavior. It is likely that different groups of genes contribute to     7     characteristics that enable us to explore. There may be other genes—7R among them—which go even further: They     8     us to explore. It helps, in short, to think not just of the urge to explore but of the ability—not just the motivation but the     9    . Before you can act on the urge, you need the tools or characteristics that make exploration     10    .

2 . Directions: Complete the following passage by using the words in the box. Each word can only be used once. Note that there is one word more than you need.

A. appears     B. changing     C. dependent       D. dim       E. discovery       F. exclusively G. reflect       H. review        I. sexually        J. underlying       K. vigorously

Undercover Wings

The nocturnal（夜间活动）dot-underwing moth（蛾）may use shape -shifting patterns on its wings as a way to attract mates in the dark. In a study published last September in Current Biology, scientists report the    1    on males' forewings of three patches（色斑）that change darkness and size when viewed from particular angles. In females, the entire forewing darkens.

Although butterfly and moth species that are active during the day are known to employ visual effects to communicate, researchers had thought their nocturnal cousins relied almost    2    on chemical signals because of the lack of light. But these    3    wing patterns, now found for the first time in a nocturnal moth, suggest the insects may also use visual signals. Because only the males have this pattern, researchers say it is likely a（n）    4    selected mechanism.

Jennifer Kelley, an ecologist based at the University of Western Australia, and her colleagues first noticed the visual phenomenon while looking at museum moth specimens（标本）for another project. "As soon as we figured the effect was angle-    5    , we knew that to understand how it works, we had to understand the    6    physics," Kelley says. The group contacted Gerd Schröder-Turk and Bodo Wilts, who are physicists at Murdoch University in Perth and the Adolphe Merkle Institute in Switzerland respectively.

Together the researchers found that when the wings are viewed from above, they    7    available light directly, like a dull mirror. When viewed from an angle, however, they let some of the light through to reveal a deeper layer of darkness, which    8    as patches on the male's wings. If the insects were to beat their wings    9    —a common behavior among males approaching potential mates—the patches would flash on and off, creating a striking signal even in very    10    light.