--- My son is to be seen. Where has he gone?
--- I think he in the building.
A. nowhere; must be hiding
B. nowhere; must be hidden himself
C. anywhere; hides
D. everywhere; hides himself
网友回答
(答案→)A. nowhere; must be hiding
B. nowhere; must be hidden himself
C. anywhere; hides
D. everywhere; hides himself
解析：考查情态动词表示推测的区别。根据后半句“Where has he gone?”可知，说话者不知道其儿子在哪里，故第一空填在哪里也不见的单词“nowhere”；另一个人说：我认为他一定正在这栋建筑里，且hide与他之间应为主动关系；故A正确。