It is required in the library regulations that any book borrowed __________ by due time, or the borrower will be fined.
The church tower, which will be open to tourists soon. The work is almost finished.
Tom was the second to reach the top of the mountain, Mike _______ the first.
This painting is so valuable that it is rather difficult to calculate _______ its price would be if the museum _______ to sell it.
While _______ driver’s licenses in China, new car drivers will have to fill out a body part donation form, which is _______ for some drivers-to-be.
The earth could be younger and took more than three times longer to form than _______ thought, according to a new study.