Finding information in today's world is easy. The ________ is how you can tell if the information you get is useful or not.
| A．knowledge | B．ability |
| C．competition | D．challenge |
____ that caused him to serve dinner an hour later than usual.
| A．It was we being late | B．It was our being late |
| C．It was we were too late | D．It was because we were late |
---- Do you know his address？
---- No, I also wish I _____ where he _____.
| A．knew, lived | B．knew, lives | C．know, lives | D．know, lived |
—John has put forward _______ most challenging question for us to answer.
—Yes, it really is. I have never heard _______ harder one.
| A．the; 不填 | B．不填; the | C．the; the | D．a; a |
Though _____, the news brought them much encouragement.
| A．surprised | B．being surprised |
| C．having surprised | D．surprising |
I have _____ an eye _____ you now, so you do as you _____!
| A．left; over; have to | B．to keep; on; were told |
| C．kept; down; have been told | D．kept; on; are told |