Interactive grammar exercise (subject-verb agreement) from “A Tree With Deep Roots” Part 2

As Ddol-bok escapes, he steals Jeong Do-gwang’s horse, which ______ the Hidden Root Scroll.
1. carries
2. carry
King Sejong officially ______ Chae-yoon to investigate who murdered the scholars.
1. appoints
2. appoint
Chae-yoon boldly ______ King Sejong to reward him with a drink if he solves the case.
1. asks
2. ask
Chae-yoon and his men ______ to Banchon where the autopsy of the murdered scholar is being carried out by Ga Ri-on.
1. go
2. goes
Scholar Sung Sam-moon and Scholar Park Paeng-nyeon ______ the rumors about the murder of their fellow scholar.
1. hear
2. hears
Chae-yoon and Cho-tak chase after an intruder in the Hall of Worthies, but a masked man ______.
1. intervenes
2. intervene
But while So-yi is inside the printing office, it ______ into flames.
1. explodes
2. explode
Chae-yoon saves So-yi from the fire but ______ her harshly on who was the masked man inside the burning office.
1. questions
2. question
But So-yi, through writing down her answers, ______ Chae-yoon’s authority and says that he’s asking the wrong questions.
1. challenges
2. challenge
Chae-yoon remarks that earth, water, and fire ______ to kill the scholars.
1. have been used
2. has been used