【推荐1】听下面一段较长对话，回答以下小题。
1. What is the purpose of the tool?

A．To restore blind people’s vision.

B．To give blind people perfect vision.

C．To prevent blindness from happening.

2. What is in the glasses?

A．A computer chip.

B．A video camera.

C．A special pen.

3. What does the man say about the tool?

A．Its working process is very fast.

B．It can help people who are born blind.

C．The glasses send pictures to people’s eyes.

【推荐1】听下面一段独白，回答以下小题。

1. What is the speaker mainly talking about?

A．A search engine.

B．A language program.

C．A special business model.

2. How many people use Duolingo currently?

A．Over one hundred million.

B．A few hundred thousand.

C．Several thousand.

3. Which country is Luis von Ahn from?

A．Switzerland.

B．Guatemala.

C．Costa Rica.

4. How was Duolingo originally funded?

A．By big websites.

B．By an actor.

C．By school.

【推荐2】听下面一段较长对话，回答以下小题。

1. What are the speakers talking about?

A．Modem technologies.

B．Teaching machines.

C．Unemployment in the future.

2. Who does the housework at the woman’s mother’s house?

A．The maid.

B．Machines.

C．The woman’s mother.

3. What do the speakers agree about machine teachers?

A．They will replace human teachers.

B．They are useful but not human.

C．They are both artists and scientists.

【推荐3】听下面一段独白，回答以下小题。
1. What problem is going to be settled?

A．Too much rain water.

B．Lack of food.

C．Polluted river systems.

2. Why is the project really exciting?

A．It helps the city become cleaner.

B．It needs to design 5 new roofs.

C．It makes full use of urban roofs.

3. What do you know about the urban agriculture?

A．It requires rebuilding the city.

B．It may be the future for food.

C．It helps citizens out of starvation.

4. What was the average produce of one green roof in the first year?

A．650.

B．700.

C．850