You'd better make a mark _____ you have any questions.

A. at which  B. at where  C. the place  D. where

You'd better make a mark _____ you have any questions.

A. at which B. at where C. the place D. where

You’d better make a mark ______ you have any questions.

A. at which 　 　 B. at where

C. the place 　 　 D. where

While reading, you'd better make a mark ___ you have any questions.

  A. on which       B. at where     C. the place where    D.where

While reading, you’d better make a mark ___ you have any questions.

A. on which   B. at which   C. the place where   D. where