请选择DCBA)[5_0h6@-d2a/Z3u-q How _______ you say that you really understand the whole story if you have covered only a part of the article?7s,c3E't8y;d5t
A. can7s,c3E't8y;d5t
B. must7s,c3E't8y;d5t
C. need7s,c3E't8y;d5t
D. may7s,c3E't8y;d5t