Biochemists have solved many of the mysteries about photosynthesis, the process ___ plants make food.
Education in many countries is compulsory________the age of 16.
According to critics of globalization, several developed countries have become rich because of
The phrase "keeps sellers on their toes" in the passage mostly means "______".
The word "allocated" in the passage mostly means "______".
I am sorry I have no time at present to____________________ detail of our plan.
We must push the piano to the corner of the hall to_____________________ our party tonight.
_______ has been a topic of continual geological research.
She asked me______I was looking at.
The pool should not be made so deep______small children can be safe there.
The boat was sailing north when a terrible storm_____________ .