单选题 He______that his guests were bored, although they were listening politely.
【正确答案】 B
【答案解析】解析：impress给……留下印象；sense感觉；infer推断；identify确认，确定。本句意为：他感觉到，虽然客人们在礼貌地倾听，但是他们已经觉得无聊了。