Being constantly exposed to advertisements is annoying but it be pleasant sometimes.A.

问题补充：

Being constantly exposed to advertisements is annoying, but it be pleasant sometimes.

A. shall

B. need

C. can

D. must

答案：

A. shall

B. need

(答案→)C. can

D. must

解析：

试题分析:考查情态动词。A将；B需要；C能够，D必须。根据语境可知前后句是转折关系，前句讲总是看广告让人恼火，所以后句应该是有时候会让人愉快，四个选项中只有can可以表示“有时也可能”，所以C选项正确。句意：总是不断地接触广告是很恼人的， 但是有时候也会让人轻松愉快。