You’d better look up the new word in a dictionary _____ you don’t know it ?

A．if                B．that              C．though           D．whether

—Do you know the meaning of the new word? It puzzles me a lot.
—I’ve no idea. But I think you can look it up in          .

— I don’t know the new word.

   — It doesn’t matter, you can ______ in the dictionary.

A. look up it                     B. look it up                      C. look for it                    D. look it for

If you don’t know how to spell the new word, please ________ in the dictionary.

 If you don’t know the new word, you’d better ＿＿.

A. look up a dictionary    B. look up an dictionary

C. look it up in a dictionary   D. look up it dictionary