When _______how a statue from distant Greece could have appeared in China, researchers explaine...

When _______how a statue from distant Greece could have appeared in China, researchers explaine...

C

试题分析：句意：当被问及来自遥远希腊的塑像怎么会出现在中国时，研究人员解释说，这无疑是亚历山大大帝的影响所致。本句是主从复合句，其中When asked how...是一个省略性状语从句，其完整形式为When they were asked how...当从句的主语和主句的主语一致时，或从句的主谓结构为it is (was)时，连词 when, while, though, if 等常引导省略性状语从句，即省略从句中的主语和be动词，选C。