The students who keeps on asking questions in the class:

The students who keeps on asking questions in the class: Correct Answer Should be encouraged for continue questioning

The students who keep on asking questions in the class should be encouraged to continue questioning.

This is an act of an active learner. 

Active learning:

• This is the most desirable method where students/learners play the central role generally.
• It focuses on 'how' they learn, not just on 'what' they learn.
• Learners are encouraged to ‘think hard’, rather than receiving information from the teacher passively.

Characteristics of active learner:

• Students directly involved in learning rather than listening only.
• They always keep on asking a question not sitting in the class passively. 
• Less emphasis is given on delivering lectures and taking notes.
• Active participation of students emphasis extending and encouraging students' ideas and skills.
• Students are involved in higher-order thinking, analysis, synthesis, and evaluation. 
• Students also engaged in activities e.g., reading, writing, discussion, etc.
• Greater emphasis is placed on students' exploration of their own attitudes, values, and prior experiences.

Conclusion: So an active learner always has the qualities stated above and it should be encouraged by the teacher.