________makes the book so extraordinary is the creative imagination of the writer.(2013·北京,31)
Though ________ money, his parents managed to send him to university.
The research is so designed that once _______ nothing can be done to change it.
“What do you think made Mary so upset?” “_______ her new bike.”
“How do you deal with the disagreement between the company and the customers?” “The key ______ the problem is to meet the demand ______ by the customers.”
The boy wanted to ride his bicycle in the street, but his mother told him ______.