61.What’s the main reason for so many new species being there?

A.The forest is located in the tropic zone.

B.The rainforests haven’t been disturbed for thousands of years.

C.The scientists’ hard work helps them live.

D.The forest is covered with all kinds of green plants.

解析：选B。细节理解题。根据第四段的“The rainforests likely have existed as continuous undisturbed forest cover for thousands of years，and，as a result，offer unique habitats for many species”可知，数千年来没有受到干扰的雨林为大量的物种提供了栖息地，这就是产生新物种的原因。

62.Three of the new orchid species are very special because ________.

A.they have no leaves at all

B.they can produce black flowers

C.they have chlorophyll

D.they don’t belong to any plants

解析：选A。细节理解题。参见倒数第二段的“Three of the new orchid species are entirely leafless，which is unusual even among orchids，containing no chlorophyll(叶绿素) commonly found in plants.”可知这种兰花特殊的原因是因为它们没有叶子。

63.What can we know from the text?

A.The central part of Vietnam is surrounded by mountains.

B.Dr.Chris Dickinson has been living in the region since the 1990s.

C.New orchid species are the most among all the new species discovered since the 1990s.

D.Scientists have been working to protect the Green Corridor in the past years.

解析：选D。推理判断题。根据第一段的最后一句“They say this proves the importance of conservation efforts in the ancient tropical forests of the region.”和第三段的内容可以推知，科学家一直在设法保护这片森林。

C

Babies who use many gestures (手势) to communicate when they are 14 months old have much larger vocabularies when they start school than those who don’t，US researchers said.

They said babies with wealthier，better­educated parents will probably sign more.This may help explain why some children from low­income families perform less well in school.

“When children enter school，there is a large difference in their vocabularies，”said the University of Chicago’s Meredith Rowe，whose study appears in the journal Science.

Gestures could help explain the difference，Rowe told the American Association for the Advancement of Science yearly meeting in Chicago.

Vocabulary is an important predictor of school success.Earlier research showed that rich，educated parents tend to talk to their children more than poorer，less­educated ones.

“What we are doing here is asking：Does this social­economic situation relate to gestures?Can that explain some of the difference we see at school entry (进入)?”Rowe said.

The researchers filmed 50 Chicago­area children and parents from different economic backgrounds and counted the number of gestures，such as pointing at a picture.