He asked where she ____, but she didn’t respond.
A number of tests have been conducted to _________ that these drugs have no side effects.
---Why did Tom become wealthy this year?---Because he sold _________________ he did last year.
Not until his father came back ____________ to bed.
The doctor said that maybe his disease is __________ the water he drinks.
It’s an agreement between towns or cities, _______ have similar features, such as industry, culture and entertainment.