单选题 Did you notice the ______ on the doctor's face when he heard that Kino had found the pearl of the world?
【正确答案】 B
【答案解析】appearance：外貌，外观；expression：表情，脸色，声调，腔调，语法，措辞；description：描写，记述，形容，种类，描述；look：看，注视，脸色，面容，外表。此句应该指的是面部表情，所以正确答案B。