By the time Jack returned home from America, his son __________ from college. [

题型：云南省期中题难度：来源：

By the time Jack returned home from America, his son __________ from college. [      ]
A. graduate
B. has graduated
C. had graduated
D. had been graduated

答案

举一反三

---European scientists announced that the speed of light isn’t the speed limit.
---Perhaps it is the biggest challenge to Einstein’s Theory of Relativity. No one _____ any crack in his
theory for more than a century. [ ]
A. has found
B. found
C. had found
D. would find

题型：江苏专项题难度：| 查看答案

They ________ with each other for two years before they got married.[     ]
A．had fallen in love
B．got in love
C．had been in love
D．fell in love

题型：同步题难度：| 查看答案

They ________ with each other for two years before they got married.[     ]
A．had fallen in love
B．got in love
C．had been in love
D．fell in love

题型：同步题难度：| 查看答案

Tom said they ________ the tomb of everything it contained before he found it.[     ]
A．have emptied
B．emptied
C．had emptied
D．empty

题型：同步题难度：| 查看答案

— Got your driving license?
— No. I ________ too busy to have enough practice, so I didn"t take the driving test last week.[     ]
A. was
B. am
C. have been
D. had been

题型：专项题难度：| 查看答案