Danby left word with my secretary ________ he would call again in the afternoon.

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

It is pretty well understood __________controls the flow of carbon dioxide in and out the atmosphere today.

A.that                  B.when             C.what                D.how 

It's reported that by the end of this week the stock exchange________ by about 10％.

A. will have risen     B. has risen      C. will be rising     D. has been rising

______was known to them all that William had broken his promise______ he would give each of them a gift.

A. As, which        B. What, that      C. It , that      D. It , which

Having been born on the earth, we had no choice but ________ hospitality it offered.

A. to accept that       B. accept how      C. to accept what      D. accept what

Never ______ such a good boss before I came to this company.

     A) do I meet        B) I met               C) had I met        D) I had met

David can speak idiomatic American English and yet, _____ English, he doesn't know it at all.

       A. how to teach               B. when it comes to teaching

C. when he teaches                     D. however he teaches

Professor Smith and Professor Brown will _____ in giving the class lectures.

A. exchange        B. alter            C. shift            D. alternate

She doubted whether he would be ______ to the task, so he was not admitted.

  A. similar        B. equal                 C.familiar     D. content

You can still find bones of the birds ________ they used to live.

A. in which       B. in the place       C. where            D. that