1 . As soon as the teacher enters the classroom, The students stand up. (Negative)

• A. No sooner does the teacher enter the classroom than the students stand up.
• B. No sooner the teacher enters the classroom than the students stand up.
• C. No sooner had the teacher entered the classroom than the students stood up.
• D. The students stood up as the teacher entered the classroom.

Answer: Option A

Explanation: