—You may find the key to the math problem on page 107．

—Ah, it's so simple. I wonder why I _____ of that．

A．hadn’t thought    B．haven't thought     C．didn't think        D．wasn't thinking

_____ the city’s public school system should be open to the children of migrant workers has become the focus of discussion.

A．That              B．What             C．Whether          D．If

I didn't realize my mother loves me so such until I received her gift for my 18th birthday, a diary______ the process of my growth．

A．recorded         B．to record          C．recording         D．having recorded

— You have helped me a lot. I can’t thank you enough.

—______.

A．Be my guest.       B．That’s right.       C．I don’t think so.    D．Think nothing of it.

— Who _____ be phoning us at this time of night?

— It might be your sister. 

A．might             B．can              C．dare             D．must

— Nowadays people seem to be becoming more and more selfish.

— How much better life would be if we ______ to the values of the past!

A．would return       B．had returned       C．return            D．were to return

Tell your doctor with a detailed medical history ______ he can give you the accurate treatment.

A．even if           B．so that            C．in case            D．as though

So absorbed _____ in the experiment that he didn’t even notice it was already over 12 o’clock.

A．did he            B．he did            C．was he            D．he was

The Nobel Prize in literature has been awarded annually to an author from any country _________ has produced "in the field of literature the most outstanding work in an ideal direction".

A．which            B．who              C．where            D．as

—Can you come up with another good idea?

—This is the best approach I can imagine __________ the work ahead of schedule.

A．to accomplish      B．to accomplishing    C．accomplishing      D．accomplished