---You may find the key to the maths problem on page 107.
---Ah, it’s so simple. I wonder why I ________ of that.
A. didn’t think B. haven’t thought C. wasn’t thinkingD. hadn’t thought
----You seem to have known Dr Smith for a long time.
---- That’s true. ______ he joined our club six years ago.
A. Since B. Until C. When D. Before
----I don’t mind telling you what I know.
----You ________. I’m not asking you for it.
A. mustn’t B. needn’t C. may not D. shouldn’t
The Mid-Autumn Day, which is a day for family reunion in China, _____ on September 12th this year.
A. falls B. fixes C. lies D. sets
Three years ago in Beijing, my best friend, David, was hit by a car while riding a bike, _______ a terrible brain injury.
A. caused B. to cause C. causing D. being caused
The rise in wood fuel use has _____ the disappearance of forest and the loss of habitats for pandas.
A. belonged to B. adapted to C. devoted to D. contributed to