高中英语人教版（2019）选修四Unit 1 Science Fiction Using Language & Assessing Your Progress同步课时训练

Everything will all right in the end.

Sometimes very odd things show up in ordinary places. In the 1800s, a strange sight began to be reported by farmers. Then in the 1970s, this strange event began to happen more and more often. People travelled for miles to stand in the fields and take photos of something they couldn't easily explain. What were they looking at? It was the crop circles—large and complex designs set into the middle of ordinary farm fields. No one could understand how these huge designs were made.

Crop circles are found most often in fields of wheat, corn, or rice. They are usually created overnight, although some are reported to have appeared during the day. They have been seen in more than 70 different countries. Scientists have found that the plants inside a crop circle are drier than the ones outside it. The plant stems (茎) are bent but not broken in most crop circles, and sometimes the soil in the design has more iron than the soil outside of the design. Unfortunately, these facts alone do not help scientists answer their questions about crop circles. These facts only make them more mysterious.

Some people believe crop circles are made by UFOs (Unidentified Flying Objects) landing in farm fields. Others think aliens are leaving us messages in the beautiful designs. Still others believe Earth energy under the ground makes plants bend over in designs. Some people say they actually made the crop circles with special equipment. Scientists have found some crop circles that are certainly made by people, but they are usually a little different from other crop circles. So who makes crop circles and why they make them can't be explained to this very day.

While the start of a new school year is always exciting, this year was even more so for some elementary school students in Auckland, New Zealand. They became the world's first kids to be "taught" by a digital teacher, just like in the science fiction. Before you start imagining a human-like robot pacing around the classroom, Will is just an avatar (化身) that appears on the students' desktop, or the smartphone screen, when ordered to come.

The autonomous animation platform has been modeled after the human brain and nervous system, allowing it to show human-like behavior. The digital teacher is assigned to teach Vector's "Be sustainable with energy"—a free program for Auckland's elementary schools.

Just like the humans it replaces, Will is able to instantly react to the students' responses to the topic. Thanks to a webcam and a microphone, the avatar not only responds to questions the kids may have, but also picks up non-verbal cues randomly. For instance, if a student smiles at Will, he responds by smiling back. This two-way interaction not only helps attract the students' attention, but also allows the program's developers to monitor their engagement, and make changes if needed.

Nikhil Ravishankar believes that Will-like avatars could be a novel way to catch the attention of the next generation. He says, "I have a lot of hopes for this technology as a means to deliver cost-effective, rich and educational experience in the future."

The program, in place since August 2018, has been a great success thus far. Ravishankar says, "What was fascinating to me was the reaction of the children to Will. The way they look at the world is so creative and different, and Will really captured their attention. However, regardless of how popular it becomes, Will is unlikely to replace human educators any time soon. "