可理解为过去分词作原因状语,逻辑主语是the professor ,形容人感到……用过去分词.
也可理解为省略句
Though(he was surprised) to see us,the professor gave us a warm welcome
当状语从句的主语与主句一致,且动词为be动词时,主语和be动词可同时省略.
所以选B应加上主语HE才行.
可理解为过去分词作原因状语,逻辑主语是the professor ,形容人感到……用过去分词.
也可理解为省略句
Though(he was surprised) to see us,the professor gave us a warm welcome
当状语从句的主语与主句一致,且动词为be动词时,主语和be动词可同时省略.
所以选B应加上主语HE才行.