There is a wide ________of reference books to be found, so ________you look for some material needed, you can turn to me.

A. kind; the last time                     B. sort; every time

C. varity; next time                       D. type; the moment

There is a wide ________of reference books to be found, so ________you look for some material needed, you can turn to me.

1. A.
   kind; the last time
2. B.
   sort; every time
3. C.
   varity; next time
4. D.
   type; the moment

There is a wide ________ of reference books to be found, so _______ you look for some

material needed, you can turn to me.

A. kind; the last time                   B. sort; every time

C. variety; next time                   D. type; the moment

There is a wide ________of reference books to be found, so ________you look for some material needed, you can turn to me.