问题
选择题
When I entered the classroom, I saw Mary ______ at the desk and ______ a letter.
A．seating; writing
B．seated; wrote
C．sitting; wrote
D．seated; writing
答案
答案：D
考查非谓语动词。第一空Mary与seat为动宾关系要用过去分词作补语，与sit为主谓关系要用现在分词作补语；第二空Mary与write为主谓关系要用现在分词作补语。故选D。句意：我走进教室看到玛丽坐在桌子旁边写信。