Choose the best answer

1. " ........ class are you in ?" " Class"
A. Which.              B. Whose.               C. Where
2. Trung : " Why do you think most people learn Enhlish ?"
A. I hear it is very good .
B. Because it ' s useful to them .
C. Because I like it
3. That is the laboratory .............  we do all our experiments 
A. Which               B. Where               C. That 
4. lt is necessary for students to listen to their teacher ..................
A. Attentive .         B. Attentivel .       C. Attending