问题
选择题
The twin brothers stand under the tree, ______ and say nothing.
A．puzzled
B．puzzling
C．being puzzling
D．being puzzled
答案
答案：A
考察非谓语动词.句意:这对双胞胎兄弟站在树下,困惑不解不说一句话.过去分词表示句子主语发生过的被动动作,和句子主语是动宾关系.puzzle意思是使……困惑的意思，故选A。