D

In a recent announcement, Harvard and the Massachusetts Institute of Technology(MIT)said that they have joined forces to offer free online courses in an effort to attract millions of online learners worldwide.

Beginning this fall, a number of courses developed by teachers at both universities will be offered online through a new $60 million program, known as edX. “Anyone with an Internet connection anywhere in the world can use our online courses,” Harvard President Drew Faust said during a meeting to announce the plan.

MIT has offered a program called OpenCourseWare for ten years that makes materials from more than 2,000 classes free online. It has been used by more than 100 million people. In December, the school announced it also would begin offering a special certificate, known as MITx, for people who complete certain online courses. Harvard has long offered courses to a wider population through a similar program.

The MITx will serve as the foundation for the new learning platform.

MIT President Susan Hockfield said more than 120,000 people signed up for the first MITx course. She said Harvard and MIT hope other universities will join them in offering courses on the open-source edX platform.

“Fasten your seatbelts,” Hockfield said.

Other universities, including Stanford, Yale and Carnegie-Mellon, have been experimenting with teaching to a global population online.

The Harvard-MIT program will be monitored by a not-for-profit(非盈利的)organization based in Cambridge, to be owned equally by the two universities. Both MIT and Harvard have provided $30 million to start the program. They also plan to use the edX platform to research how students learn and which teaching methods and tools are most successful.

53. According to this text, edX is _______.

A. a part of the free MIT OpenCourseWare

B. a free computer program by MIT and Harvard

C. a Harvard-MIT platform of free online courses

D. a free program online for universities worldwide

54. What is said about online education in the text?

A. Universities have been trying online courses.

B. About 2,000 online courses have been offered.

C. Over 100 million people have finished courses online.

D. Stanford and Yale together have courses similar to edX.

55. The underlined part in the text probably means “ ”.

A. Get ready for the difficulties

B. Get ready for this educational change

C. Get prepared to complete the online courses

D. Get prepared to make materials for the edX courses

56. What can be said about MITx according to the text?

A. It is first offered as part of the edX learning program.

B. It is another free MIT-Harvard online learning program.

C. It is a standard to recognize online learners’ achievement.

D. It is a new kind of free online course of Harvard and MIT.

E

Plants are flowering faster than scientists predicted(预测)in reaction to climate change, which could have long damaging effects on food chains and ecosystems.

Global warming is having a great effect on hundreds of plant and animal species around the world, changing some living patterns, scientists say.

Increased carbon dioxide(CO2)in the air from burning coal and oil can have an effect on how plants produce oxygen, while higher temperatures and changeable rainfall patterns can change their patterns of growth.

“Predicting species’ reaction to climate change is a major challenge in ecology,” said the researches of several U.S. universities. They said plants had been the key object of study because their reaction to climate change could have an effect on food chains and ecosystem services.

The study, published on the Nature website, uses the findings from plant life cycle studies and experiments across four continents and 1,634 species. It found that some experiments had underestimated(低估)the speed of flowering by 8.5 times and leafing by 4 times.

“Across all species, the experiments under-predicted the speed of the advance — for both leafing and flowering — that results from temperature increases,” the study said.

The design of future experiments may need to be improved to better predict how plants will react to climate change, it said.

Plants are necessary for life on the Earth. They are the base of the food chain, using photosynthesis(光合作用)to produce sugar from carbon dioxide and water. They let out oxygen which is needed by nearly every organism on the planet.

Scientists believe the world’s average temperature has risen by about 0.8℃ since 1900, and nearly 0.2℃ every ten years since 1979.

So far, efforts to cut emissions(排放)of planet-warming greenhouse gases are not seen as enough to prevent the Earth heating up beyond 2℃ this century — a point scientists say will bring the danger of a changeable climate in which weather extremes are common, leading to drought, floods, crop failures and rising sea levels.