______ he met with the difficulty did he realize the importance of our help.
| A．Even though | B．Never until | C．Only before | D．Ever since |
—What is the man, do you know?
—I don’t know exactly. But I think he can be but a teacher.
| A．anybody | B．something | C．anything | D．everybody |
sometimes keeps her awake at night Tom is getting more and more quiet at home.
| A．That; which | B．It; that | C．Whether; what | D．What; that |
Mrs. Black took the police back to place she witnessed the robbery.
| A．the same; as | B．the same; where | C．the same; that | D．as the same; as |
—The English exam is not difficult, is it?
— . Even Tom to the top students failed in it.
| A．yes; belonged | B．No; belonged | C．Yes; belonging | D．No; belonging |
Ask American which city has the worst air pollution, and the answer is sure to be Los Angeles.
| A．some | B．every | C．any | D．all |