8.  It may have to do with how a teacher talks to the class: many positive, supportive expressions and few expressions of impatience, annoyance, or irritation. Non-verbal communication, including ______ expressions, probably plays a role too.
【正确答案】 A
【答案解析】 形容词词义辨析。facial“面部的，用面部的”；variable“变化的，可变的”；suggestive“提示的，暗示的，使人联想的”；emotional“情绪的，情感的”。根据空格前的Non-verbal communication判定，选项中，只有facial与expressions(面部的表情)搭配符合语义。