Choose the word of phrase that best fits the blank space in the following passage
I’m (1) _______________ to hear you had an (2) _______________ Christmas vacation. I (3) _______________ my first report few days ago. I got good grades (4) _______________ English, but my math result (5) _______________ poor. My math teacher asked me to spend more time on it. I must study (6) _______________ for the next semester.
Question 4:
A. at
B. in
C. so
D. for