B

He Jiang，who was the first person from China to deliver a Harvard University commencement(学位授予典礼)address，has made the 2017 Forbes 30 Under 30 List．

Forbes’30 Under 30 is a set of lists issued annually by Forbes magazine．On Tuesday，the magazine published the sixth annual 30 Under 30，featuring 600 young inventors and leaders who challenge conventional wisdom and rewrite the rules for the next generation．

The list recognizes 30 game-changers in each of 20 industries．All under 30 years old，the candidates were examined by a group of judges in their fields．“The winners are the people that will run every field for the next 50 years，”said Randall Lane．editor of Forbes．

He，a 29-year-old postdoctoral fellow at the Massachusetts Institute of Technology，was chosen for the healthcare category．He was recommended by his professors at Harvard．

At Harvard，He used a new technology to understand more about how flu infects cells，and discovered human genes with strong anti-viral effects．He is now applying the same techniques to white blood cells．He hopes the lab research he did could be put to practical use in healthcare．

He grew up in a small village with limited educational opportunities．By studying hard，He graduated from the University of Science and Technology of China with a bachelor’s degree in 2009，told was accepted into Harvard’s PhD program on a full scholarship the same year．

In May，the biochemistry PhD delivered a speech representing the university’s 13 graduate and professional schools at the ceremony．In the speech，He talked about the unbalanced distribution of science and technology in the world and expressed his passion to get science and medicine into places they aren’t reaching，like his own village，where his mother once treated his spider bite with fire．

25．Why can He Jiang be on the 2017 Forbes under 30 list?

A．He was recommended by Randall lane．

B．He has made outstanding contributions in healthcare．

C．Fie made a speech at the Harvard commencement．

D．He changed the regulations for the next generation．

26．What will He Jiang intend to do in the future?

A．Know more about the infection of flu．

B．Apply the same technology to blood cells.

C．Put his research into practice in medical care．

D．Discover human genes’strong anti-viral effects．

27．What can we infer from the last paragraph?

A．His mother is a doctor． B．He wants to help backward areas．

C．He got a full PhD scholarship． D．His university has only 13 graduates．

 

C

Deliberately making a road icy sounds like a method for disaster，but in 16th-century China it helped things run smoothly．Repairs to the Forbidden City in Beijing in 1557 called for huge stones from a quarry(采石场)more than 70 km away．The biggest was the 300-ton“Large Stone Carving．”Such stones were too heavy for any cart，and too fragile for rollers．The builders adopted a wise alternative approach to carry the heavy stone．

They dug a series of wells，spaced a few hundred metres apart，along the route to the quarry．Then，in the depth of winter，when temperatures reached around -4℃，buckets of water were poured on to the dirt track，transforming it into an ice road．

The stone blocks were pushed along the road on wooden sledges(雪橇)．Modern engineers have calculated that it would take 1，500 workers to drag a sledge on the dirt road，but only 300 on ice．Ancient texts suggested the ice was made slippery with more water；this reduced the friction further and just 50 men could pull a sledge．This technique only works when the temperature is close to zero，otherwise the fi lm of water freezes too quickly．

The researchers at Princeton University estimated that the blocks could be moved at six metres a minute，and the journey could be completed in 28 days．This would be well before the spring when the ice would melt．

It was once suggested that similar ice-sledges transported Stonehenge stones，but the ground that had a lot of holes and comparatively mild conditions probably rule this out．

28．Why did people dig some wells along the road to the quarry?

A．They wanted to build frozen roads．

B．They wanted to break up large stones．

C．They wanted to make the dirty track clean．

D．They wanted to get a lot of holes on the road．

 

29．What did people do to reduce the friction?

A．They made stone blocks much smaller．

B．They poured more water on the ice road．

C．They waited until the temperature was very low．

D．They asked more than l，500 workers to clean the dirty road．

30．How did the researchers at Princeton University think of Stonehenge stones?

A．They were not likely to be carried on the icy road．

B．They had a longer history than stones in Beijing．

C．They were carried for over twenty-eight days．

D．They were broken up in the depth of winter．

31．What does the author intend to tell us in the text?

A．Making a road slippery on purpose may be a bad idea．

B．The mild weather helped to carry Stonehenge stones．

C．Stonehenge stones were too heavy to carry．