题目内容：

    Professor Ashok Goel of Georgia Tech developed an artificially intelligent teaching assistant to help handle the enormous number of student questions in the online class, Knowledge-Based Artificial Intelligence. Professor Goel already had eight teaching assistants, but that wasn’t enough to deal with the overwhelming number of daily questions from students.

Many students drop out of online courses because of the lack of teaching support. When students feel ignored or confused and reach out with questions that go unanswered, their motivation to continue begins to taper off. Professor Goel decided to do something to improve this situation and his solution was to create a virtual assistant named Jill Watson.

Goel and his team developed several versions of Jill Watson before releasing her to the online forums. At first, the virtual assistant wasn’t too great. But Goel and his team sourced the online discussion forum to find all the 40,000 questions that had ever been asked since the class was launched. Then they began to feed Jill with the questions and answers. After some adjustments and sufficient time, Jill was able to answer the students’ questions correctly 97% of the time. The virtual assistant became so advanced and realistic that the students didn’t know she was a computer. The students, who were studying artificial intelligence, were interacting with the virtual assistant and couldn’t tell it apart from a real human being. Goel didn’t inform them about Jill’s true identity until April 26. The students were actually very positive about the experience.

The goal of Professor Goel’s virtual assistant next year is to take over answering 40% of all the questions posed by students on the online forum. Professor Goel has a much rosier outlook on the future of artificial intelligence.

1.What problem did Professor Goel meet with?

A.Students’ questions were too many to deal with.

B.Teaching assistants were not professional at all.

C.Many students were lack of interest in his class.

D.He felt confused about how to teach online.

2.Which of the following best explains the underlined phrase in Paragraph 2?

A.grow dramatically B.increase sharply

C.decrease gradually D.decline unreasonably

3.What do we learn about Jill Watson?

A.She could answer all questions without mistakes.

B.She turned out to be a great success.

C.Her performance was remarkable all the way.

D.Her true identity was still a secret to students.

4.What’s the main idea of the text?

A.A robot gives an online course.

B.Virtual assistant is getting popular in school.

C.Robots will replace humans in online classes.

D.One Georgia Tech’s teaching assistant isn’t human.