_____ leaves the room last ought to turn off the lights.
| A．Anyone | B．The person | C．Whoever | D．Who |
After chatting online for along time, Mary looked up, ＿＿that it was 11：00 pm, long past her usual bedtime.
| A．to see | B．saw | C．seeing | D．seen |
He is a strict but kind teacher, ＿＿my son loves and respects.
| A．one | B．he | C．the one who | D．he who |
-I've studied watching birds as one of my interests. Could I make some suggestions?
――＿＿
| A．You will make it | B．It doesn't matter |
| C．Go right ahead | D．Take it easy |
David said that it was because of his strong interest in literature＿＿he chose the course.
| A．that | B．what | C．why | D．how |
No matter how frequently＿＿，the works of Beethoven still attract people all over the world.
| A．performed | B．performing |
| C．to be performed | D．being performed |