Đọc đoạn văn sau và chọn câu trả lời đùng cho các câu hỏi. 
Artificial intelligence is the technology that allows machines to possess human-like intelligence. It means creating intelligence artifically. The machines or robots are programmed so that they can think like humans and act like them. It is believed that machines can be programmed to possess cognitive abilities. Al robots can think, make the most appropriate decisions and learn from past experiences without any human intervention. This concept is called machine learning which is a sub-branch of artificial intelligence. 
Artificial intelligence can be classified into two different types, namely - weak Al and strong AL Weak Al involves performing some tasks like answering questions and performing basic tasks like setting the alarm, playing music, or making a call. Strong Al refers to performing others that involve problem-solving and decision-making without human intervention. This type of Al is found in smart robots, self-driving cars. 
(Adapted from universal-robots.com) 
21. What could be the best title for the passage? 
A. Two different types of Al          B. What are Al robots? 
C. What is Al?                              D. Smart machines 
22. What does an Al machine possess? 
A. Al robots                       B. classified intelligence 
C. human intelligence       D. human-like intelligence 
23. The word "they in paragraph 1 refers to 
A. The programs       C. The robots 
B. The machines       D. The machines or robots 
24. The word "classified" in paragraph 2 can be replaced by 
A. divided      C. provided      B. controlled      D. performed