The letters for the boss on his desk but he didn’t read them until 3 days later.
A. were put
B. was put
C. put
D. has put
网友回答
(答案→)A. were put
B. was put
C. put
D. has put
解析：考查时态语态。letter“信件”和put“放”之间是被动的关系，所以排除C和D，然后因为letters
是复数，所以选择A选项。句意：给老板的那些信放在他的办公桌上，但是直到三天以后他才
读了那些信。