【题目】From the address________on the envelope，we see that the letter is from America.
A.marking
B.marked
C.to be marked
D.having marked

【答案】B
【解析】考查非谓语动词。mark与address为逻辑上的动宾关系，故用动词ed形式作定语。C项不定式常用来表示动作将要发生。