. There is such an occasion ___________ we know lots of words, but we can’t choose a suitable one to express ourselves.

A. where                  B. when                 C. which                D. what

. There is such an occasion ___________ we know lots of words, but we can’t choose a suitable one to express ourselves.

A. where               B. when               C. which              D. what

. There is such an occasion ___________ we know lots of words, but we can’t choose a suitable one to express ourselves.

 There is such an occasion ___________ we know lots of words, but we can’t choose a suitable one to express ourselves．

A．where         when           C．which           D．what