About _______ gene-targeting drugs are already in testing pipeline. It won’t be long ______ they are put into effect.
The job was a great challenge and the bad weather _________ our difficulties.
It is said that this is the biggest lab ________ they have ever built in their school.
In order to attract more customers, many supermarkets usually sell their goods at a good________ at weekends.
It will be at least three weeks________ he recovers from his illness and returns to work.
He found his house broken into and many things stolen _______ his return from office.