Tired of the president’s speech the people at the back began to play with their mobile

问题补充：

Tired of the president’s speech, the people at the back began to play with their mobile phone.

A. boring, seating

B. bored, seated

C. boring, sitting

D. bored, having been seated

答案：

A. boring, seating

B. bored, seated

(答案→)C. boring, sitting

D. bored, having been seated

解析：考查形容词辨析。现在分词转换的形容词通常用来形容物，过去分词转换的形容词通常用来形容词人或者与人有关的事物。Boring令人厌倦的；通常用来修饰物。seated就坐的；第二空的seated/sitting at the back 是定语修饰名词，在句中表示状态。句意：对于主席令人厌倦的研究感到厌倦，坐在后排的人开始玩起了手机。